Apostrophe

Historical development

The apostrophe was first used by Pietro Bembo in his edition of De Aetna (1496). It was introduced into English in the 16th century in imitation of French practice.

French practice

Introduced by Geoffroy Tory (1529), the apostrophe was used in place of a vowel letter to indicate elision (as in l’heure in place of la heure). It was frequently used in place of a final e (which was still pronounced at the time) when it was elided before a vowel, as in un’ heure. Modern French orthography has restored the spelling une heure.

Early English practice

From the 16th century, following French practice, the apostrophe was used when a vowel letter was omitted either because of incidental elision (I’m for I am) or because the letter no longer represented a sound (lov’d for loved). English spelling retained many inflections that were not pronounced as syllables, notably verb endings (-est, -eth, -es, -ed) and the noun ending -es, which marked either plurals or possessives (also known as genitives; see Possessive apostrophe, below). So apostrophe followed by s was often used to mark a plural, especially when the noun was a loan word (and especially a word ending in a, as in the two comma’s).

Standardisation

The use of elision has continued to the present day, but significant changes have been made to the possessive and plural uses. By the 18th century, apostrophe + s was regularly used for all possessive singular forms, even when the letter e was not omitted (as in the gate’s height). This was regarded as representing the Old English genitive singular inflection -es. The plural use was greatly reduced, but a need was felt to mark possessive plural. The solution was to use an apostrophe after the plural s (as in girls’ dresses). However, this was not universally accepted until the mid-19th century.

Possessive apostrophe

The apostrophe is used to indicate possession. This convention distinguishes possessive singular forms (Bernadette’s, flower’s, glass’s, one’s) from simple plural forms (Bernadettes, flowers, glasses, ones), and both of those from possessive plural forms (Bernadettes’, flowers’, glasses’, ones’). For singulars, the modern possessive or genitive inflection is a survival from certain genitive inflections in Old English, and the apostrophe originally marked the loss of the old e (for example, lambes became lamb’s).

General principles for the possessive apostrophe

Summary of rules for most situations

Possessive personal pronouns, serving as either noun-equivalents or adjective-equivalents, do not use an apostrophe, even when they end in s. The complete list of those ending in the letter s or the corresponding sound /s/ or /z/ but not taking an apostrophe is ours, yours, his, hers, its, theirs, and whose.

Other pronouns, singular nouns not ending in s, and plural nouns not ending in s all take ’s in the possessive: e.g., someone’s, a cat’s toys, women’s.

Plural nouns already ending in s take only an apostrophe after the pre-existing s when the possessive is formed: e.g., three cats' toys.

Basic rule (singular nouns)

For most singular nouns the ending 's is added; e.g., the cat’s whiskers.

If a singular noun ends with an s-sound (spelled with -s, -se, for example), practice varies as to whether to add 's or the apostrophe alone. A widely accepted practice is to follow whichever spoken form is judged better: the boss’s shoes, Mrs Jones’ hat (or Mrs Jones’s hat, if that spoken form is preferred). In many cases, both spoken and written forms differ between writers. (See details below.)

Acronyms and initialisms used as nouns (CD, DVD, NATO, RADAR, etc.) follow the same rules as singular nouns: e.g., "the TV's picture quality".

Basic rule (plural nouns)

When the noun is a normal plural, with an added s, no extra s is added in the possessive; so the neighbours' garden (where there is more than one neighbour) is correct rather than the neighbours's garden.

If the plural is not one that is formed by adding s, an s is added for the possessive, after the apostrophe: children’s hats, women’s hairdresser, some people’s eyes (but compare some peoples’ recent emergence into nationhood, where peoples is meant as the plural of the singular people). These principles are universally accepted.

A few English nouns have plurals that are not spelled with a final s but nevertheless end in an /s/ or a /z/ sound: mice (plural of mouse; also in compounds like dormouse, titmouse), dice (when used as the plural of die), pence (a plural of penny, with compounds like sixpence that now tend to be taken as singulars). In the absence of specific exceptional treatment in style guides, the possessives of these plurals are formed by adding an apostrophe and an s in the standard way: seven titmice’s tails were found, the dice’s last fall was a seven, his few pence’s value was not enough to buy bread. These would often be rephrased, where possible: the last fall of the dice was a seven.

Basic rule (compound nouns)

Compound nouns have their singular possessives formed with an apostrophe and an added s, in accordance with the rules given above: the Attorney-General’s husband; the Lord Warden of the Cinque Ports's prerogative; this Minister for Justice’s intervention; her father-in-law’s new wife.

In such examples, the plurals are formed with an s that does not occur at the end: e.g., attorneys-general. A problem therefore arises with the possessive plurals of these compounds. Sources that rule on the matter appear to favour the following forms, in which there is both an s added to form the plural, and a separate s added for the possessive: the attorneys-general’s husbands; successive Ministers for Justice’s interventions; their fathers-in-law’s new wives. Because these constructions stretch the resources of punctuation beyond comfort, in practice they are normally reworded: interventions by successive Ministers for Justice.

Joint or separate possession

For two nouns (or noun phrases) joined by and, there are several ways of expressing possession, including:

1. marking of the last noun (e.g. "Jack and Jill's children")2. marking of both nouns (e.g. "Jack's and Jill's children").

Some grammars make no distinction in meaning between the two forms. Some publishers' style guides, however, make a distinction, assigning the "segregatory" (or "distributive") meaning to the form "John's and Mary's" and the "combinatorial" (or "joint") meaning to the form "John and Mary's". A third alternative is a construction of the form "Jack's children and Jill's", which is always distributive, i.e. it designates the combined set of Jack's children and Jill's children.

When a coordinate possessive construction has two personal pronouns, the normal possessive inflection is used, and there is no apostrophe (e.g. "his and her children"). The issue of the use of the apostrophe arises when the coordinate construction includes a noun (phrase) and a pronoun. In this case, the inflection of only the last item may sometimes be, at least marginally, acceptable ("you and your spouse's bank account"). The inflection of both is normally preferred (e.g. Jack's and your dogs), but there is a tendency to avoid this construction, too, in favour of a construction that does not use a coordinate possessive (e.g. by using "Jack's letters and yours"). Where a construction like "Jack's and your dogs" is used, the interpretation is usually "segregatory" (i.e. not joint possession).

With other punctuation; compounds with pronouns

If the word or compound includes, or even ends with, a punctuation mark, an apostrophe and an s are still added in the usual way: "Westward Ho!’s railway station"; "Awaye!’s Paulette Whitten recorded Bob Wilson’s story"; Washington, D.C.’s museums, assuming that the prevailing style requires full stops in D.C.

If the word or compound already includes a possessive apostrophe, a double possessive results: Tom’s sisters’ careers; the head of marketing’s husband’s preference; the master of foxhounds’ best dog’s death. Many style guides, while allowing that these constructions are possible, advise rephrasing: the head of marketing’s husband prefers that .... If an original apostrophe, or apostrophe with s, occurs at the end, it is left by itself to do double duty: Our employees are better paid than McDonald’s employees; Standard & Poor’s indices are widely used: the fixed forms of McDonald’s and Standard & Poor’s already include possessive apostrophes. For similar cases involving geographical names, see below.

Similarly, the possessives of all phrases whose wording is fixed are formed in the same way:

"Us and Them"’s inclusion on the album The Dark Side of the Moon

You Am I’s latest CD

The 69’ers’ drummer, Tom Callaghan (only the second apostrophe is possessive)

His ’n’ Hers’s first track is called "Joyriders".

Was She's success greater, or King Solomon’s Mines's?

For complications with foreign phrases and titles, see below.

Time, money, and similar

An apostrophe is used in time and money references, among others, in constructions such as one hour’s respite, two weeks’ holiday, a dollar’s worth, five pounds’ worth, one mile’s drive from here. This is like an ordinary possessive use. For example, one hour’s respite means a respite of one hour (exactly as the cat’s whiskers means the whiskers of the cat). Exceptions are accounted for in the same way: three months pregnant (in modern usage, one says neither pregnant of three months, nor one month(’)s pregnant).

Possessive pronouns and adjectives

No apostrophe is used in the following possessive pronouns and adjectives: yours, his, hers, ours, its, theirs, and whose.

The possessive of it was originally it’s, and many people continue to write it this way, though the apostrophe was dropped in the early 1800s and authorities are now unanimous that it’s can be only a contraction of it is or it has. For example, U.S. President Thomas Jefferson used it’s as a possessive in his instructions dated 20 June 1803 to Lewis for his preparations for his great expedition.

All other possessive pronouns ending in s do take an apostrophe: one’s; everyone’s; somebody’s, nobody else’s, etc. With plural forms, the apostrophe follows the s, as with nouns: the others’ husbands (but compare They all looked at each other’s husbands, in which both each and other are singular).

Importance for disambiguation

Each of these four phrases (listed in Steven Pinker’s The Language Instinct) has a distinct meaning:

My sister’s friend’s investments (the investments belonging to a friend of my sister)

My sister’s friends’ investments (the investments belonging to several friends of my sister)

My sisters’ friend’s investments (the investments belonging to a friend of several of my sisters)

My sisters’ friends’ investments (the investments belonging to several friends of several of my sisters)

Kingsley Amis, on being challenged to produce a sentence whose meaning depended on a possessive apostrophe, came up with:

Those things over there are my husband’s. (Those things over there belong to my husband.)

Those things over there are my husbands’. (Those things over there belong to several husbands of mine.)

Those things over there are my husbands. (I'm married to those men over there.)

Singular nouns ending with an "s" or "z" sound

This subsection deals with singular nouns pronounced with a sibilant sound at the end: /s/ or /z/. The spelling of these ends with -s, -se, -z, -ze, -ce, -x, or -xe.

Many respected authorities recommend that practically all singular nouns, including those ending with a sibilant sound, have possessive forms with an extra s after the apostrophe so that the spelling reflects the underlying pronunciation. Examples include Oxford University Press, the Modern Language Association, the BBC and The Economist. Such authorities demand possessive singulars like these: Senator Jones’s umbrella; Tony Adams’s friend. Rules that modify or extend the standard principle have included the following:

If the singular possessive is difficult or awkward to pronounce with an added sibilant, do not add an extra s; these exceptions are supported by The Guardian, Yahoo! Style Guide, and The American Heritage Book of English Usage. Such sources permit possessive singulars like these: Socrates’ later suggestion; or Achilles’ heel if that is how the pronunciation is intended.

Classical, biblical, and similar names ending in a sibilant, especially if they are polysyllabic, do not take an added s in the possessive; among sources giving exceptions of this kind are The Times and The Elements of Style, which make general stipulations, and Vanderbilt University, which mentions only Moses and Jesus. As a particular case, Jesus'  is very commonly written instead of Jesus’s – even by people who would otherwise add ’s in, for example, James’s or Chris’s. Jesus’  is referred to as "an accepted liturgical archaism" in Hart’s Rules.

Although less common, some contemporary writers still follow the older practice of omitting the extra s in all cases ending with a sibilant, but usually not when written -x or -xe. Some contemporary authorities such as the Associated Press Stylebook recommend or allow the practice of omitting the extra "s" in all words ending with an "s", but not in words ending with other sibilants ("z" and "x"). The 15th edition of The Chicago Manual of Style recommended the traditional practice, which included providing for several exceptions to accommodate spoken usage such as the omission of the extra s after a polysyllabic word ending in a sibilant, but the 16th edition no longer recommends omitting the extra "s".

Similar examples of notable names ending in an s that are often given a possessive apostrophe with no additional s include Dickens and Williams. There is often a policy of leaving off the additional s on any such name, but this can prove problematic when specific names are contradictory (for example, St James’ Park in Newcastle [the football ground] and the area of St. James's Park in London). Having said that, there has been ongoing debate around the punctuation of St James' Park (Newcastle) for some time, contrary to St James's Park (London) which is the less contentious version. For more details on practice with geographic names, see the relevant section below.

Some writers like to reflect standard spoken practice in cases like these with sake: for convenience' sake, for goodness’ sake, for appearance' sake, for compromise’ sake, etc. This punctuation is preferred in major style guides. Others prefer to add ’s: for convenience’s sake. Still others prefer to omit the apostrophe when there is an s sound before sake: for morality’s sake, but for convenience sake.

The Supreme Court of the United States is split on whether a possessive singular noun that ends with s should always have an additional s after the apostrophe, sometimes have an additional s after the apostrophe (for instance, based on whether the final sound of the original word is pronounced /s/ or /z/), or never have an additional s after the apostrophe. The informal majority view (5–4, based on past writings of the justices) has favoured the additional s, but a strong minority disagrees.

Nouns ending with silent s, x, or z

The English possessive of French nouns ending in a silent s, x, or z is addressed by various style guided. Certainly a sibilant is pronounced in examples like Descartes’s and Dumas’s; the question addressed here is whether s needs to be added. Similar examples with x or z: Sauce Périgueux’s main ingredient is truffle; His pince-nez’s loss went unnoticed; "Verreaux(’s) eagle, a large, predominantly black eagle, Aquila verreauxi,..." (OED, entry for "Verreaux", with silent x; see Verreaux’s eagle); in each of these some writers might omit the added s. The same principles and residual uncertainties apply with "naturalised" English words, like Illinois and Arkansas.

For possessive plurals of words ending in silent x, z or s, the few authorities that address the issue at all typically call for an added s and suggest that the apostrophe precede the s: The Loucheux’s homeland is in the Yukon; Compare the two Dumas’s literary achievements. The possessive of a cited French title with a silent plural ending is uncertain: "Trois femmes’s long and complicated publication history", but "Les noces' singular effect was 'exotic primitive'..." (with nearby sibilants -ce- in noces and s- in singular). Compare treatment of other titles, above.

Guides typically seek a principle that will yield uniformity, even for foreign words that fit awkwardly with standard English punctuation.

Possessives in geographic names

Place names in the United States do not use the possessive apostrophe on federal maps and signs. The United States Board on Geographic Names, which has responsibility for formal naming of municipalities and geographic features, has deprecated the use of possessive apostrophes since 1890 so as not to show ownership of the place. Only five names of natural features in the US are officially spelled with a genitive apostrophe: Martha’s Vineyard; Ike’s Point, New Jersey; John E’s Pond, Rhode Island; Carlos Elmer's Joshua View, Arizona; and Clark's Mountain, Oregon.

Australia’s Intergovernmental Committee on Surveying and Mapping also has a no-apostrophe policy, a practice it says goes back to the 1900s and which is generally followed around the country.

On the other hand, the United Kingdom has Bishop’s Stortford, Bishop’s Castle and King’s Lynn (among many others) but St Albans, St Andrews and St Helens. London Underground’s Piccadilly line has the adjacent stations of Earl’s Court in Earls Court and Barons Court. These names were mainly fixed in form many years before grammatical rules were fully standardised. While Newcastle United play football at a stadium called St James’ Park, and Exeter City at St James Park, London has a St James’s Park (this whole area of London is named after the parish of St James’s Church, Piccadilly). The special circumstances of the latter case may be this: the customary pronunciation of this place name is reflected in the addition of an extra -s; since usage is firmly against a doubling of the final -s without an apostrophe, this place name has an apostrophe. This could be regarded as an example of a double genitive: it refers to the park of the parish of St James.

Modern usage has been influenced by considerations of technological convenience including the economy of typewriter ribbons and films, and similar computer character "disallowance" which tend to ignore traditional canons of correctness. Practice in the United Kingdom and Canada is not so uniform.

Possessives in names of organizations

Sometimes the apostrophe is omitted in the names of clubs, societies, and other organizations, even though the standard principles seem to require it: Country Women’s Association, but International Aviation Womens Association; Magistrates’ Court of Victoria, but Federated Ship Painters and Dockers Union. Usage is variable and inconsistent. Style guides typically advise consulting an official source for the standard form of the name (as one would do if uncertain about other aspects of the spelling of the name); some tend towards greater prescriptiveness, for or against such an apostrophe. As the case of womens shows, it is not possible to analyze these forms simply as non-possessive plurals, since women is the only correct plural form of woman.

Possessives in business names

Where a business name is based on a family name it should in theory take an apostrophe, but many leave it out (contrast Sainsbury’s with Harrods). In recent times there has been an increasing tendency to drop the apostrophe. Names based on a first name are more likely to take an apostrophe, but this is not always the case. Some business names may inadvertently spell a different name if the name with an s at the end is also a name, such as Parson. A small activist group called the Apostrophe Protection Society has campaigned for large retailers such as Harrods, Currys, and Selfridges to reinstate their missing punctuation. A spokesperson for Barclays PLC stated, "It has just disappeared over the years. Barclays is no longer associated with the family name." Further confusion can be caused by businesses whose names look as if they should be pronounced differently without an apostrophe, such as Paulos Circus, and other companies that leave the apostrophe out of their logos but include it in written text, such as Cadwalader’s.

Apostrophe showing omission

An apostrophe is commonly used to indicate omitted characters, normally letters:

It is used in contractions, such as can't from cannot, it’s from it is or it has, and I’ll from I will or I shall.

It is used in abbreviations, as gov’t for government. It may indicate omitted numbers where the spoken form is also capable of omissions, as ’70s for 1970s representing seventies for nineteen-seventies. In modern usage, apostrophes are generally omitted when letters are removed from the start of a word, particularly for a compound word. For example, it is not common to write ’bus (for omnibus), ’phone (telephone), ’net (Internet). However, if the shortening is unusual, dialectal or archaic, the apostrophe may still be used to mark it (e.g., ’bout for about, ’less for unless, ’twas for it was). Sometimes a misunderstanding of the original form of a word results in an incorrect contraction. A common example: ’til for until, though till is in fact the original form, and until is derived from it.

The spelling fo’c’s’le, contracted from the nautical term forecastle, is unusual for having three apostrophes. The spelling bo’s’n’s (from boatswain’s), as in Bo’s’n’s Mate, also has three apostrophes, two showing omission and one possession. Fo’c’s’le may also take a possessive s – as in the fo’c’s’le’s timbers – giving four apostrophes in one word. A word which formerly contained two apostrophes is sha'n't for shall not, examples of which may be found in the older works of P G Wodehouse and "Frank Richards" (Charles Hamilton), but this has been superseded by shan't.

It is sometimes used when the normal form of an inflection seems awkward or unnatural; for example, KO’d rather than KOed (where KO is used as a verb meaning "to knock out"); "a spare pince-nez’d man" (cited in OED, entry for "pince-nez"; pince-nezed is also in citations).

An apostrophe’s function as possessive or contractive can depend on the grammatical context:

We rehearsed for Friday’s opening night. (We rehearsed for the opening night on Friday.)

We rehearsed because Friday’s opening night. (We rehearsed because Friday is opening night. "Friday’s" here is a contraction of "Friday is.")

Eye dialects use apostrophes in creating the effect of a non-standard pronunciation.

Apostrophes to omit letters in place names are common on British road signs when space does not allow for the full name (e.g. Wolverhampton abbreviated as "W’hampton" and Kidderminster as "K’minster", as shown on this sign).

Use in forming some plurals

The plural of single lowercase letters is usually indicated by adding an apostrophe and an s, as in

"dot the i's and cross the t's"

The apostrophe may also be used for clarity in other cases of single letters or digits, as in

"Find all the number 7's.""She can't tell her M's from her N's."

An apostrophe is used by some writers to form a plural for abbreviations, initials including acronyms, and symbols, especially where adding just s rather than 's may leave meaning ambiguous or presentation inelegant. Some specific cases:

For groups of years, some style guides prefer 1960s to 1960’s and 90s or ’90s to 90’s or ’90's. This use of an apostrophe may be more acceptable in American than in British English.

The apostrophe is sometimes used in forming the plural of numbers, for example 1000’s of years. An alternative is to write out the numbers as words.

The apostrophe is often used in plurals of symbols, for example "that page has too many &’s and #’s on it". Some style guides state that the apostrophe is unnecessary since there is no ambiguity but that some editors and teachers prefer this usage. The addition of an 's' without an apostrophe may make the text difficult to read.

For abbreviations, acronyms, etc., use of s without an apostrophe is now more common than its use with an apostrophe, but for single lowercase letters, pluralization with -'s is usual.

Use in non-English names

Names that are not strictly native to English sometimes have an apostrophe substituted to represent other characters (see also As a mark of elision, below).

Anglicised versions of Irish surnames often contain an apostrophe after an O, for example O’Doole.

Some Scottish and Irish surnames use an apostrophe after an M, for example M’Gregor. The apostrophe here may be seen as marking a contraction where the prefix Mc or Mac would normally appear. However, it may also arise from confusion of ‘ (turned comma or "6-quote"), which was used as a substitute for superscript c when printing with hand-set metal type. Compare: M’Lean, M^cLean, M‘Lean.

Use in transliteration

In transliterated foreign words, an apostrophe may be used to separate letters or syllables that otherwise would likely be interpreted incorrectly. For example:

in the Arabic word mus'haf, a transliteration of مصحف‎, the syllables are as in mus·haf, not mu·shaf

in the Japanese name Shin'ichi, the apostrophe shows that the pronunciation is shi·n·i·chi (hiragana しんいち), where the letters n (ん) and i (い) are separate morae, rather than shi·ni·chi (しにち).

in the Chinese Pinyin romanization, when two hanzi are combined to form one word, if the resulting Pinyin representation can be misinterpreted they should be separated by an apostrophe. For example, 先 (xiān) 西安 (xī'ān).

Furthermore, an apostrophe may be used to indicate a glottal stop in transliterations. For example:

in the Arabic word Qur'an, a common transliteration of (part of) القرآن‎ al-qur'ān, the apostrophe corresponds to the diacritic Maddah over the 'alif, one of the letters in the Arabic alphabet

Rather than ʿ the apostrophe is sometimes used to indicate a voiced pharyngeal fricative as it sounds and looks like the glottal stop to most English speakers. For example:

in the Arabic word Ka'aba for الكعبة‎ al-kaʿbah, the apostrophe corresponds to the Arabic letter ʿayn.

Non-standard English use

Failure to observe standard use of the apostrophe is widespread and frequently criticised as incorrect, often generating heated debate. The British founder of the Apostrophe Protection Society earned a 2001 Ig Nobel prize for "efforts to protect, promote and defend the differences between plural and possessive". A 2004 report by British examination board OCR stated that "the inaccurate use of the apostrophe is so widespread as to be almost universal". A 2008 survey found that nearly half of the UK adults polled were unable to use the apostrophe correctly.

Superfluous apostrophes ("greengrocers' apostrophes")

Apostrophes used in a non-standard manner to form noun plurals are known as greengrocers' apostrophes or grocers' apostrophes, often called (spelled) greengrocer's apostrophes and grocer's apostrophes. They are sometimes humorously called greengrocers apostrophe's, rogue apostrophes, or idiot's apostrophes (a literal translation of the German word Deppenapostroph, which criticises the misapplication of apostrophes in Denglisch). The practice, once common and acceptable (see Historical development), comes from the identical sound of the plural and possessive forms of most English nouns. It is often criticised as a form of hypercorrection coming from a widespread ignorance of the proper use of the apostrophe or of punctuation in general. Lynne Truss, author of Eats, Shoots & Leaves, points out that before the 19th century, it was standard orthography to use the apostrophe to form a plural of a foreign-sounding word that ended in a vowel (e. g., banana's, folio's, logo's, quarto's, pasta's, ouzo's) to clarify pronunciation. Truss says this usage is no longer considered proper in formal writing.

The term is believed to have been coined in the middle of the 20th century by a teacher of languages working in Liverpool, at a time when such mistakes were common in the handwritten signs and advertisements of greengrocers (e. g., Apple's 1/- a pound, Orange's 1/6d a pound). Some have argued that its use in mass communication by employees of well-known companies has led to the less literate assuming it to be correct and adopting the habit themselves.

The same use of apostrophe before noun plural -s forms is sometimes made by non-native speakers of English. For example, in Dutch, the apostrophe is inserted before the s when pluralising most words ending in a vowel or y for example, baby's (English babies) and radio's (English "radios"). This often produces so-called "Dunglish" errors when carried over into English. Hyperforeignism has been formalised in some pseudo-anglicisms. For example, the French word pin's (from English pin) is used (with the apostrophe in both singular and plural) for collectable lapel pins. Similarly, there is an Andorran football club called FC Rànger's (after such British clubs as Rangers F.C.), a Japanese dance group called Super Monkey's, and a Japanese pop punk band called the Titan Go King's.

Omission

In the UK there is a tendency to drop apostrophes in many commonly used names such as St Annes, St Johns Lane, and so on.

In 2009 a resident in Royal Tunbridge Wells was accused of vandalism by one neighbour after he painted apostrophes on road signs that had spelled the street name as St Johns Close.

UK supermarket chain Tesco omits the mark where standard practice would require it. Signs in Tesco advertise (among other items) "mens magazines", "girls toys", "kids books" and "womens shoes". In his book Troublesome Words, author Bill Bryson lambastes Tesco for this, stating that "the mistake is inexcusable, and those who make it are linguistic Neanderthals."

Particular cases

George Bernard Shaw, a proponent of English spelling reform on phonetic principles, argued that the apostrophe was mostly redundant. He did not use it for spelling cant, hes, etc., in many of his writings. He did, however, allow I’m and it’s. Hubert Selby, Jr. used a slash instead of an apostrophe mark for contractions and did not use an apostrophe at all for possessives. Lewis Carroll made greater use of apostrophes, and frequently used sha’n’t, with an apostrophe in place of the elided "ll" as well as the more usual "o". These authors’ usages have not become widespread.

Other misuses

The British pop group Hear’Say famously made unconventional use of an apostrophe in its name. Truss comments that "the naming of Hear’Say in 2001 was [...] a significant milestone on the road to punctuation anarchy". Dexys Midnight Runners, on the other hand, omit the apostrophe (though "dexys" can be understood as a plural form of "dexy", rather than a possessive form).

An apostrophe wrongly thought to be misused is in the name of rock band The La’s. This apostrophe is often thought to be a mistake; but in fact it marks omission of the letter d. The name comes from the Scouse slang for "The Lads".

The over-use of apostrophes in names in fantasy literature was satirised by Neal Stephenson in Reamde.

Criticism

Over the years, the use of apostrophes has been criticised. George Bernard Shaw called them "uncouth bacilli". In his book American Speech, linguist Steven Byington stated of the apostrophe that "the language would be none the worse for its abolition." Adrian Room in his English Journal article "Axing the Apostrophe" argued that apostrophes are unnecessary and context will resolve any ambiguity. In a letter to the English Journal, Peter Brodie stated that apostrophes are "largely decorative...[and] rarely clarify meaning". Dr. John C. Wells, Emeritus Professor of Phonetics at University College London, says the apostrophe is "a waste of time".

As a mark of elision

In many languages, especially European languages, the apostrophe is used to indicate the elision of one or more sounds, as in English.

In Albanian the apostrophe is used to show that a vowel has been omitted from words, especially in different forms of verbs and in some forms of personal pronoun. For example, t’i them (from të + i them), m’i mori (from më + i mori). It is used too in some of the forms of possessive pronouns, for example: s’ëmës (from së ëmës).

In Afrikaans the apostrophe is used to show that letters have been omitted from words. The most common use is in the indefinite article ’n, which is a contraction of een meaning "one" (the number). As the initial e is omitted and cannot be capitalised, if a sentence begins with ’n the second word in the sentence is capitalised. For example: ’n Boom is groen, "A tree is green". In addition, the apostrophe is used for plurals and diminutives where the root ends with long vowels, e.g. foto’s, taxi’s, Lulu’s, Lulu’tjie, etc.

In Danish, apostrophes are sometimes seen on commercial materials. One might commonly see Ta' mig med ("Take me with [you]") next to a stand with advertisement leaflets; that would be written Tag mig med in standard orthography. As in German, the apostrophe must not be used to indicate the possessive, except when there is already an s, x or z present in the base form, as in Lukas’ bog ("the Gospel of Luke").

In Dutch, the apostrophe is used to indicate omitted characters. For example, the indefinite article een can be shortened to 'n, and the definite article het shortened to 't. When this happens in the first word of a sentence, the second word of the sentence is capitalised. In general, this way of using the apostrophe is considered non-standard, except in 's morgens, 's middags, 's avonds, 's nachts (for des morgens, des middags, des avonds, des nachts: "at morning, at afternoon, at evening, at night"). In addition, the apostrophe is used for plurals where the singulars end with long vowels, e.g. foto’s, taxi’s; and for the genitive of proper names ending with these vowels, e.g. Anna’s, Otto’s. These are in fact elided vowels; use of the apostrophe prevents spellings like fotoos and Annaas.

In Esperanto, the Fundamento limits the elision mark to the definite article l’ (from la) and singular nominative nouns (kor’ from koro, "heart"). This is mostly confined to poetry. Idiomatic phrases such as dank’ al (from (kun) danko al, "thanks to") and del’ (from de la, "of the") are nonetheless frequent. In-word elision is usually marked with a hyphen, as in D-ro (from doktoro, "Dr"). Some early guides used and advocated the use of apostrophes between word parts, to aid recognition of such compound words as gitar’ist’o, "guitarist".

In Catalan, French, Italian, Ligurian, and Occitan word sequences such as (coup) d’état, (maître) d’hôtel (often shortened to maître d’, when used in English), L’Aquila and L’Hospitalet de Llobregat the final vowel in the first word (de "of", la "the", etc.) is elided because the word that follows it starts with a vowel or a mute h. Similarly, French has qu’il instead of que il ("that he"), c’est instead of ce est ("it is or it’s"), and so on. Catalan, French, Italian, and Occitan surnames sometimes contain apostrophes of elision, e.g. d’Alembert, D’Angelo.

French feminine singular possessive adjectives do not undergo elision, but change to the masculine form instead: ma preceding église becomes mon église ("my church").

Quebec's Bill 101, which dictates the use of French in the province, prohibits the use of apostrophes in proper names in which it would not be used in proper French (thus the international donut chain Tim Hortons, originally spelled with the possessive apostrophe as Tim Horton’s, was required to drop the apostrophe in Quebec to comply with Bill 101).

Galician language standard admits the use of apostrophe (apóstrofo) for contractions that normally don’t use (e.g.: de + a= da) it but when the second element is a proper noun, mostly a title: o heroe d’A Odisea (the heroe of the Odyssey). They are also used to reproduce oral ellisions and, as stated below, to join (or split) commercial names of popular public establishments, namely bars and in masculine (O’Pote, The pot), maybe pretending to remind anglicised versions of Irish surnames.

In Ganda, when a word ending with a vowel is followed by a word beginning with a vowel, the final vowel of the first word is elided and the initial vowel of the second word lengthened in compensation. When the first word is a monosyllable, this elision is represented in the orthography with an apostrophe: in taata w’abaana "the father of the children", wa ("of") becomes w’; in y’ani? ("who is it?"), ye ("who") becomes y’. But the final vowel of a polysyllable is always written, even if it is elided in speech: omusajja oyo ("this man"), not *omusajj’oyo, because omusajja ("man") is a polysyllable.

In modern printings of Ancient Greek, apostrophes are also used to mark elision. Some Ancient Greek words that end in short vowels elide when the next word starts with a vowel. For example, many Ancient Greek authors would write δἄλλος (d’állos) for δὲ ἄλλος (dè állos) and ἆροὐ (âr’ ou) for ἆρα οὐ (âra ou). Such modern usage should be carefully distinguished from polytonic Greek's native rough and smooth breathing marks, which usually appear as a form of rounded apostrophe.

In Hebrew, the geresh (׳), often typed as an apostrophe, is used to denote initialisms. A double geresh (״), known by the plural form gershayim, is used to denote acronyms; it is inserted before (i.e., to the right of) the last letter of the acronym. Examples: פרופ׳ (abbreviation for פרופסור, "profesor", 'professor'); נ״ב ("nun-bet", 'P.S.'). The geresh is also used to indicate the elision of a sound; however, this use is much less frequent, and confined to the purpose of imitating a natural, informal utterance, for example: אנ׳לא ("anlo" – short for אני לא, "ani lo", 'I am/do not').

In Irish, the past tense of verbs beginning with an F or vowel begins with d' (elision of do), for example do oscail becomes d’oscail ("opened") and do fhill becomes d’fhill ("returned"). The copula is is often elided to 's, and do ("to"), mo ("my") etc. are elided before f and vowels.

In Italian it is used for elision with pronouns, as in l’ha instead of la ha, articles, as in l’opera instead of la opera, and for truncation, as in po’ instead of poco.

In modern Norwegian, the apostrophe marks that a word has been contracted, such as "ha’kke" from "har ikke" (have/has not). Unlike English and French, such elisions are not accepted as part of standard orthography but are used to create a more "oral style" in writing. The apostrophe is also used to mark the genitive for words that end in an -s sound: words ending in -s, -x, and -z, some speakers also including words ending in the sound [ʃ]. As Norwegian doesn't form the plural with -s, there is no need to distinguish between an -s forming the possessive and the -s forming the plural. Therefore, we have "mann" (man) and "manns" (man’s), without apostrophe, but "los" (naval pilot) and "los’" (naval pilot’s). Indicating the possessive for former American Presidents George Bush, whose names end in [ʃ], could be written as both Bushs (simply adding an -s to the name) and Bush’ (adding an apostrophe to the end of the name).

In Portuguese the apostrophe is also used in a few combinations, such as caixa-d’água ("water tower"), galinha-d’angola ("guineafowl"), pau-d’alho ("Gallesia integrifolia"), etc. Portuguese has many contractions between prepositions and articles or pronouns (like na for em + a), but these are written without an apostrophe.

Modern Spanish no longer uses the apostrophe to indicate elision in standard writing, although it can sometimes be found in older poetry for that purpose. Instead Spanish writes out the spoken elision in full (de enero, mi hijo) except for the contraction del for de + el, which uses no apostrophe. Spanish also switches to a form that is identical to the masculine article (but is actually a variant of the feminine article) immediately before a feminine noun beginning with a stressed a instead of writing (or saying) an elision: un águila blanca, el águila blanca, and el agua pura but una/la blanca águila and la pura agua. This reflects the origin of the Spanish definite articles from the Latin demonstratives ille/illa/illum.

In Swedish, the apostrophe marks an elision, such as "på sta’n", short for "på staden" ("in the city"), to make the text more similar to the spoken language. This is relaxed style, fairly rarely used, and would not be used by traditional newspapers in political articles, but could be used in entertainment related articles and similar. The formal way to denote elision in Swedish is by using colon, e.g. S:t Erik for Sankt Erik which is rarely spelled out in full. The apostrophe must not be used to indicate the possessive except – although not mandatory – when there is already an s, x or z present in the base form, as in Lukas’ bok.

German usage is very similar: an apostrophe is used almost exclusively to indicate omitted letters. It must not be used for plurals or most of the possessive forms (The only exception being the possessive cases of names ending in an s-sound as in Max’ Vater, or "to prevent ambiguities" in all other possessive cases of names as Andrea’s Blumenladen. The latter use is discouraged, while being formally correct); although both usages are widespread, they are deemed incorrect. The German equivalent of greengrocers’ apostrophes would be the derogatory Deppenapostroph ("idiots’ apostrophe"; see the article Apostrophitis in German Wikipedia).

Welsh uses the apostrophe to mark elision of the definite article yr ("the") following a vowel (a, e, i, o, u, y, w in Welsh), such as i’r tŷ "to the house". It is also used with the particle yn, such as with mae hi’n "she is".

As a glottal stop

Several languages and transliteration systems use the apostrophe or some similar mark to indicate a glottal stop, sometimes considering it a letter of the alphabet:

In several Finno-Ugric languages, such as Estonian and Finnish.

In Guarani, it is called puso /puˈso/, and used in the words ñe’ẽ (language, to speak), ka’a (grass), a’ỹ (sterile).

In Hawaiian, the ʻokina ⟨ʻ⟩, an inverted apostrophe, is often rendered as ⟨'⟩. It is considered a letter of the alphabet.

Mayan.

In the Tongan language, the apostrophe is called a fakauʻa and is the last letter of the alphabet. It represents the glottal stop. Like the ʻokina, it is inverted.

Various other Austronesian languages, such as Samoan, Tahitian, and Chamorro.

Tetum, one of the official languages of East Timor.

The Brazilian native Tupi language.

In Võro, the apostrophe is used in parallel with the letter "q" as symbol of plural.

Several fictional languages such as Klingon, D’ni, Mando’a or Na’vi.

The apostrophe represents sounds resembling the glottal stop in the Turkic languages and in some romanizations of Semitic languages, including Arabic. In typography, this function may be performed by the closing single quotation mark. In that case, the Arabic letter ‘ayn (ع) is correspondingly transliterated with the opening single quotation mark.

As a mark of palatalization or non-palatalization

Some languages and transliteration systems use the apostrophe to mark the presence, or the lack of, palatalization:

In Belarusian and Ukrainian, the apostrophe is used between a consonant and a following "soft" (iotified) vowel (Be.: е, ё, ю, я; Uk.: є, ї, ю, я) to indicate that no palatalization of the preceding consonant takes place, and the vowel is pronounced in the same way as at the beginning of the word. It therefore marks a morpheme boundary before /j/, and in Ukrainian, is also occasionally as a "quasi letter". It appears frequently in Ukrainian, as, for instance, in the words: <п'ять> [p"jat'] 'five', <від'їзд> [vid'jizd] 'departure', <об'єднаний> [ob'jednanyj] 'united', <з'ясувати> [z'jasuvaty] 'to clear up, explain', <п'єса> [p'jesa] play (drama), etc.

In Russian and some derived alphabets the same function is served by the hard sign (ъ, formerly called yer). But the apostrophe saw some use as a substitute after 1918, when Soviet authorities enforced an orthographic reform by confiscating type bearing that "letter parasite" from stubborn printing houses in Petrograd.

In some Latin transliterations of certain Cyrillic alphabets (for Belarusian, Russian, and Ukrainian), the apostrophe is used to replace the soft sign (ь, indicating palatalization of the preceding consonant), e.g., Русь is transliterated Rus’ according to the BGN/PCGN system. (The prime symbol is also used for the same purpose.) Some of these transliteration schemes use a double apostrophe ( " ) to represent the apostrophe in Ukrainian and Belarusian text, e.g. Ukrainian слов’янське ("Slavic") is transliterated as slov"yans’ke.

Some Karelian orthographies use an apostrophe to indicate palatalization, e.g. n'evvuo ("to give advice"), d'uuri ("just (like)"), el'vüttiä ("to revive").

To separate morphemes

Some languages use the apostrophe to separate the root of a word and its affixes, especially if the root is foreign and unassimilated. (For another kind of morphemic separation see pinyin, below.)

In Danish an apostrophe is sometimes used to join the enclitic definite article to words of foreign origin, or to other words that would otherwise look awkward. For example, one would write IP'en to mean "the IP address". There is some variation in what is considered "awkward enough" to warrant an apostrophe; for instance, long-established words such as firma ("company") or niveau ("level") might be written firma'et and niveau'et, but will generally be seen without an apostrophe. Due to Danish influence, this usage of the apostrophe can also be seen in Norwegian, but is non-standard – a hyphen should be used instead: e.g. CD-en (the CD).

In Estonian, apostrophes can be used in the declension of some foreign names to separate the stem from any declension endings; e.g., Monet' (genitive case) or Monet'sse (illative case) of Monet (name of the famous painter).

In Finnish, apostrophes are used in the declension of foreign names or loan words that end in a consonant when written but are pronounced with a vowel ending, e.g. show'ssa ("in a show"), Bordeaux'hun ("to Bordeaux"). For Finnish as well as Swedish, there is a closely related use of the colon.

In Polish, the apostrophe is used exclusively for marking inflections of words and word-like elements (but not acronyms – a hyphen is used instead) whose spelling conflicts with the normal rules of inflection. This mainly affects foreign words and names. For instance, one would correctly write Kampania Ala Gore'a for "Al Gore's campaign". In this example, Ala is spelt without an apostrophe, since its spelling and pronunciation fit into normal Polish rules; but Gore'a needs the apostrophe, because e disappears from the pronunciation, changing the inflection pattern. This rule is often misunderstood as calling for an apostrophe after all foreign words, regardless of their pronunciation, yielding the incorrect Kampania Al'a Gore'a, for example. The effect is akin to the greengrocers’ apostrophe (see above).

In Turkish, proper nouns are capitalised and an apostrophe is inserted between the noun and any following suffix, e.g. İstanbul’da ("in Istanbul"), contrasting with okulda ("in school").

In Welsh the apostrophe is used with infixed pronouns in order to distinguish them from the preceding word (e.g. a’m chwaer "and my sister" as opposed to am chwaer "about a sister").

Miscellaneous uses in other languages

In Breton, the combination c'h is used for the consonant /x/ (like ch in English Loch Ness), while ch is used for the consonant /ʃ/ (as in French chat or English she).

In Czech, an apostrophe is used for writing to indicate spoken or informal language where the writer wants to express the natural way of informal speech, but it should not be used in formal text or text of a serious nature. E.G: Instead of "četl" ("he read"), the word form "čet'" is used. "Čet'" is the informal variant of the verb form "četl", at least in some varieties. These two words are the same in meaning, but to use the informal form gives the text a more natural tone, as though a friend were talking to you. Furthermore, the same as in the Slovak case above holds for lowercase t and d, and for the two-digit year notation.

In Finnish, one of the consonant gradation patterns is the change of a k into a hiatus, e.g. keko → keon ("a pile → a pile's"). This hiatus has to be indicated in spelling with an apostrophe if a long vowel or a diphthong would be immediately followed by the final vowel, e.g. ruoko → ruo'on, vaaka → vaa'an. (This is in contrast to compound words, where the equivalent problem is solved with a hyphen, e.g. maa-ala, "land area".) Similarly, the apostrophe is used to mark the hiatus (contraction) that occurs in poetry, e.g. miss’ on for missä on ("where is").

In Ganda, ng' (pronounced /ŋ/) is used in place of ŋ on keyboards where this character is not available. The apostrophe distinguishes it from the letter combination ng (pronounced [ŋɡ]), which has separate use in the language. Compare this with the Swahili usage above.

In Hebrew, the geresh (a diacritic similar to the apostrophe and often represented by one) is used for several purposes other than to mark an elision:

As an adjacent to letters to show sounds that are not represented in the Hebrew alphabet. Sounds such as /dʒ/ (English j as in "job"), /θ/ (English th as in "thigh"), and /tʃ/ (English ch as in "check") are indicated using ג, ת, and צ with a geresh (informally "chupchik"). For example, the name George is spelled ג׳ורג׳ in Hebrew (with ג׳ representing the first and last consonants).

To denote a Hebrew numeral (e.g., נ׳, which stands for "50").

To denote a Hebrew letter which stands for itself (e.g., מ׳ – the letter Mem).

Gershayim (a double geresh) to denote a Hebrew letter name (e.g., למ״ד – the letter Lamed).

Another (rarer) use of geresh is to denote the last syllable (which in some cases, but not all, is a suffix) in some words of Yiddish origin (e.g., חבר׳ה, מיידל׳ה).

In the Middle Ages and the Early modern period, gershayim were also used to denote foreign words, as well as a means of emphasis.

In Italian, an apostrophe is sometimes used as a substitute for a grave or an acute accent after a final vowel: in capitals, or when the proper form of the letter is unavailable. So Niccolò might be rendered as Niccolo', or NICCOLO'; perché, as perche', or PERCHE'. This applies only to machine or computer writing, in the absence of a suitable keyboard. This usage is considered incorrect, or at least inelegant, by many.

In Jèrriais, one of the uses of the apostrophe is to mark gemination, or consonant length. For example, t’t represents /tː/, s’s /sː/, n’n /nː/, th’th /ðː/, and ch’ch /ʃː/ (contrasted with /t/, /s/, /n/, /ð/, and /ʃ/).

In standard Lojban orthography, the apostrophe is a letter in its own right (called y'y [əhə]) that can appear only between two vowels, and is phonemically realised as either [h] or, more rarely, [θ].

In Macedonian the apostrophe is sometimes used to represent the sound schwa, which can be found on dialectal levels, but not in the Standard Macedonian.

In Slovak, the caron over lowercase t, d, l, and uppercase L consonants resembles an apostrophe: ď, ť, ľ, Ľ. This is especially so in certain common typographic renderings. But it is non-standard to use an apostrophe instead of the caron. There is also l with an acute accent: ĺ, Ĺ. In Slovak the apostrophe is properly used only to indicate elision in certain words (tys', as an abbreviated form of ty si ("you are"), or hor' for hore ("up")); however, these elisions are restricted to poetry (with a few exceptions). Moreover, the apostrophe is also used before a two-digit year number (to indicate the omission of the first two digits): '87 (usually used for 1987).

In Swahili, an apostrophe after ng shows that there is no sound of /ɡ/ after the /ŋ/ sound; that is, that the ng is pronounced as in English singer, not as in English finger.

In the new Uzbek Latin alphabet adopted in 2000, the apostrophe serves as a diacritical mark to distinguish different phonemes written with the same letter: it differentiates o' (corresponding to Cyrillic ў) from o, and g' (Cyrillic ғ) from g. This avoids the use of special characters, allowing Uzbek to be typed with ease in ordinary ASCII on any Latin keyboard. In addition, a postvocalic apostrophe in Uzbek represents the glottal stop phoneme derived from Arabic hamzah or ‘ayn, replacing Cyrillic ъ.

In the pinyin (hànyǔ pīnyīn) system of romanization for Standard Chinese, an apostrophe is often loosely said to separate syllables in a word where ambiguity could arise. Example: the standard romanization for the name of the city Xī'ān includes an apostrophe to distinguish it from a single-syllable word xian. More strictly, however, it is correct to place an apostrophe only before every a, e, or o that starts a new syllable after the first if it is not preceded by a hyphen or a dash. Examples: Tiān'ānmén, Yǎ'ān; but simply Jǐnán, in which the syllables are ji and nan, since the absence of an apostrophe shows that the syllables are not jin and an (contrast Jīn'ān). This is a kind of morpheme-separation marking (see above).

In the largely superseded Wade–Giles romanization for Standard Chinese, an apostrophe marks aspiration of the preceding consonant sound. Example: in tsê (pinyin ze) the consonant represented by ts is unaspirated, but in ts’ê (pinyin ce) the consonant represented by ts' is aspirated.

In some systems of romanization for the Japanese, the apostrophe is used between moras in ambiguous situations, to differentiate between, for example, na and n + a. (This is similar to the practice in Pinyin mentioned above.)

In English Yorkshire dialect, the apostrophe is used to represent the word the, which is contracted to a more glottal (or "unreleased") /t/ sound. Most users will write in t'barn ("in the barn"), on t'step ("on the step"); and those unfamiliar with Yorkshire speech will often make these sound like intuh barn and ontuh step. A more accurate rendition might be in't barn and on't step, though even this does not truly convey correct Yorkshire pronunciation as the t is more like a glottal stop.

Galician restaurants sometimes use O' in their names instead of the standard article O ("The").

In Switzerland, the apostrophe is used as thousands separator alongside the fixed space (e.g., 2'000'000 or 7006200000000000000♠2000000 for two million) in all four national languages.

In science fiction and fantasy, the apostrophe is often used in fictional names, sometimes to indicate a glottal stop (for example Mitth'raw'nuruodo in Star Wars), but also sometimes simply for decoration.

Typographic form

The form of the apostrophe originates in manuscript writing, as a point with a downwards tail curving clockwise. This form was inherited by the typographic apostrophe ( ’ ), also known as the typeset apostrophe, or, informally, the curly apostrophe. Later sans-serif typefaces had stylised apostrophes with a more geometric or simplified form, but usually retaining the same directional bias as a closing quotation mark.

With the invention of the typewriter, a "neutral" quotation mark form ( ' ) was created to economize on the keyboard, by using a single key to represent: the apostrophe, both opening and closing single quotation marks, single primes, and on some typewriters the exclamation point by overprinting with a period. This is known as the typewriter apostrophe or vertical apostrophe. The same convention was adopted for quotation marks.

Both simplifications carried over to computer keyboards and the ASCII character set. However, although these are widely used due to their ubiquity and convenience, they are deprecated in contexts where proper typography is important.

Unicode

Unicode defines three apostrophe characters:

U+0027 ' apostrophe

Typewriter apostrophe.

U+2019 ’ RIGHT SINGLE QUOTATION MARK

Punctuation apostrophe. Serves as both an apostrophe and closing single quotation mark. This is the preferred character to use for apostrophe according to the Unicode standard.

U+02BC ʼ MODIFIER LETTER APOSTROPHE

Modifier letters in Unicode generally are considered part of a word, this is preferred when the apostrophe is considered as a letter in its own right, rather than punctuation that separates letters. Thus this letter apostrophe may be used, for example, in the transliteration of the Arabic glottal stop (hamza) or the Cyrillic "soft sign", or in some orthographies such as cʼh of Breton, where this combination is an independent trigraph. Some consider, though, that this character should be used for the apostrophe in English instead of U+0027 or U+2019. Also ICANN considers U+02BC as a proper character for Ukrainian apostrophe within IDNs. This character is rendered identically to U+2019 in the Unicode code charts. As the distinction between the letter apostrophe and the punctuation apostrophe may not be used in practice, the Unicode standard cautions that one should never assume text is coded thus.

Characters similar to apostrophe:

U+0060 ` GRAVE ACCENT

U+00B4 ´ ACUTE ACCENT

U+02B9 ʹ MODIFIER LETTER PRIME

U+02BB ʻ MODIFIER LETTER TURNED COMMA

The Hawaiian glottal stop, the ʻokina, has its own Unicode character. It also might be used for the transliteration of Arabic and Hebrew ʻayn.

U+02BD ʽ MODIFIER LETTER REVERSED COMMA

U+02BE ʾ MODIFIER LETTER RIGHT HALF RING

Arabic hamza and Hebrew alef.

U+02BF ʿ

Arabic and Hebrew ʿayin.

U+02C8 ˈ MODIFIER LETTER VERTICAL LINE

Stress accent or dynamic accent.

U+02CA ˊ MODIFIER LETTER ACUTE ACCENT

U+02EE ˮ MODIFIER LETTER DOUBLE APOSTROPHE

One of two characters for glottal stop in Nenets.

U+0313 ̓ COMBINING COMMA ABOVE

Also known as combining Greek psili.

U+0314 ̔ COMBINING REVERSED COMMA ABOVE

Also known as combining Greek dasia.

U+0315 ̕ COMBINING COMMA ABOVE RIGHT

U+0343 ̓ COMBINING GREEK KORONIS

Identical to U+0313.

U+0374 ʹ GREEK NUMERAL SIGN

Also known as Greek dexia keraia.

U+0384 ΄ GREEK TONOS

U+055A ՚ ARMENIAN APOSTROPHE

U+1FBD ᾽ GREEK KORONIS

U+1FBF ᾿ GREEK PSILI

U+2032 ′ PRIME

U+A78B Ꞌ LATIN CAPITAL LETTER SALTILLO

Saltillo of the languages of Mexico.

U+A78C ꞌ LATIN SMALL LETTER SALTILLO

U+FF07 ＇ FULLWIDTH APOSTROPHE

Fullwidth form of the typewriter apostrophe.

ASCII encoding

The typewriter apostrophe ( ' ) was inherited by computer keyboards, and is the only apostrophe character available in the (7-bit) ASCII character encoding, at code value 0x27 (39). As such, it is a highly overloaded character. In ASCII, it represents a left single quotation mark, right single quotation mark, apostrophe, vertical line or prime (punctuation marks), or an acute accent (modifier letters).

Many earlier (pre-1985) computer displays and printers rendered the ASCII apostrophe as a typographic apostrophe, and rendered the ASCII grave accent ( ` ) U+0060 as a matching left single quotation mark. This allowed a more typographic appearance of text: ``I can't'' would appear as ‘‘I can’t’’ on these systems. This can still be seen in many documents prepared at that time, and is still used in the TeX typesetting system to create typographic quotes.

Typographic apostrophe in 8-bit encodings

Support for the typographic apostrophe ( ’ ) was introduced in several 8-bit character encodings, such as the Apple Macintosh operating system’s Mac Roman character set (in 1984), and later in the CP1252 encoding of Microsoft Windows. There is no such character in ISO-8859-1.

Microsoft Windows CP1252 (sometimes incorrectly called ANSI or ISO-Latin) contains the typographic apostrophe at 0x92. Due to "smart quotes" in Microsoft software converting the ASCII apostrophe to this value, other software makers have been forced to adopt this as a de facto convention. For instance the HTML 5 standard specifies that this value is interpreted as CP1252. Some earlier non-Microsoft browsers would display a '?' for this and make web pages composed with Microsoft software somewhat hard to read.

Entering apostrophes

Although ubiquitous in typeset material, the typographic apostrophe ( ’ ) is rather difficult to enter on a computer, since it does not have its own key on a standard keyboard. Outside the world of professional typesetting and graphic design, many people do not know how to enter this character and instead use the typewriter apostrophe ( ' ). The typewriter apostrophe has always been considered tolerable on Web pages because of the egalitarian nature of Web publishing, the low resolution of computer monitors in comparison to print, and legacy limitations provided by ASCII.

More recently, the correct use of the typographic apostrophe is becoming more common on the Web due to the wide adoption of the Unicode text encoding standard, higher-resolution displays, and advanced anti-aliasing of text in modern operating systems. Because typewriter apostrophes are now often automatically converted to typographic apostrophes by word processing and desktop publishing software (see below), the typographic apostrophe does often appear in documents produced by non-professionals.

XML (and hence XHTML) defines an ' character entity reference for the ASCII typewriter apostrophe. No equivalent entity is defined in the HTML 4 standard, despite all the other predefined character entities from XML being defined in HTML. If it cannot be entered literally in HTML, a numeric character reference could be used instead, such as ' or '. ' is officially supported in HTML since HTML 5.

Smart quotes

To make typographic apostrophes easier to enter, word processing and publishing software often converts typewriter apostrophes to typographic apostrophes during text entry (at the same time converting opening and closing single and double quotes to their correct left-handed or right-handed forms). A similar facility may be offered on web servers after submitting text in a form field, e.g. on weblogs or free encyclopedias. This is known as the smart quotes feature; apostrophes and quotation marks that are not automatically altered by computer programs are known as dumb quotes.

Such conversion is not always done in accordance with the standards for character sets and encodings. Additionally, many such software programs incorrectly convert a leading apostrophe to an opening quotation mark (e.g., in abbreviations of years: ‘29 rather than the correct ’29 for the years 1929 or 2029 (depending on context); or ‘twas instead of ’twas as the archaic abbreviation of it was). Smart quote features also often fail to recognise situations when a prime rather than an apostrophe is needed; for example, incorrectly rendering the latitude 49° 53′ 08″ as 49° 53’ 08”.

In Microsoft Word it is possible to turn smart quotes off (in some versions, by navigating through Tools, AutoCorrect, AutoFormat as you type, and then unchecking the appropriate option). Alternatively, typing Control-Z (for Undo) immediately after entering the apostrophe will convert it back to a typewriter apostrophe. In Microsoft Word for Windows, holding down the Control key while typing two apostrophes will produce a single typographic apostrophe.

Programming

Some programming languages, like Pascal, use the ASCII apostrophe to delimit string literal. In JavaScript (and ECMAScript, which is nearly identical), Perl, PHP, and Python, and many other languages either the apostrophe or the double quote may be used, allowing string literals to contain the other character (but not to contain both without using an escape character).

The C programming language (and many related languages like C++, Java, C#, and Scala) uses apostrophes to delimit a character literal. In these languages a character is a different object than a 1-letter string.

In Visual Basic (and earlier Microsoft BASIC dialects such as QuickBASIC) an apostrophe is used to denote the start of a comment.