Italian orthography

Alphabet

The base alphabet consists of 21 letters: five vowels (A, E, I, O U) and 16 consonants. The letters J, K, W, X and Y are not part of the proper alphabet, and are used only for loanwords (e.g. 'jeans') and foreign names (with very few exceptions, such as in the native names Jesolo, Bettino Craxi, and Juventus, all of which derived from regional languages). In addition, grave, acute and circumflex accents may be used to modify vowel letters.

Vowels

The Italian alphabet has five vowel letters, ⟨a e i o u⟩. Of those, only ⟨a⟩ represents one sound value while each of the others has two. In addition, ⟨e⟩ and ⟨i⟩ indicate a different pronunciation of a preceding ⟨c⟩ or ⟨g⟩ (see below).

In stressed syllables, ⟨e⟩ represents both open /ɛ/ and close /e/. Similarly, ⟨o⟩ represents both open /ɔ/ and close /o/ (see the Italian phonology for further details on these sounds). There is typically no orthographic distinction between the open and closed sounds represented, though accent marks are used in certain instances (see below). In unstressed syllables, only the close variants occur except before sonorants.

In addition to representing the respective vowels /i/ and /u/, ⟨i⟩ and ⟨u⟩ also typically represent the semivowels /j/ and /w/, respectively, when unstressed and occurring before another vowel. Many exceptions exist (e.g. attuale, deciduo, deviare, dioscuro, fatuo, iato, inebriare, ingenuo, liana, proficuo, riarso, viaggio). Unstressed ⟨i⟩ may represent that a preceding or following ⟨c⟩ or ⟨g⟩ is 'soft' (dolce).

C and G

Normally, ⟨c⟩ and ⟨g⟩ represent the plosives /k/ and /ɡ/, respectively, unless they precede a front vowel (⟨i⟩ or ⟨e⟩) when they represent the affricates /tʃ/ (like English ch) and /dʒ/ (like English j).

The letter ⟨i⟩ may also function merely as an indicator that the preceding ⟨c⟩ or ⟨g⟩ is soft, e.g. cia (/tʃa/), giu (/dʒu/). When the hard pronunciation occurs before a front vowel, digraphs ⟨ch⟩ and ⟨gh⟩ are used, so that ⟨che⟩ represents /ke/ or /kɛ/ and ⟨chi⟩ represents /ki/ or /kj/. In the evolution of the Latin language, the postalveolar affricates /tʃ/ and /dʒ/ were contextual variants of the velar consonants /k/ and /ɡ/. They eventually came to be full phonemes, and the said orthographic practice was introduced to distinguish them. The phonemicity of the affricates can be demonstrated with the minimal pairs:

The trigraphs ⟨cch⟩ and ⟨ggh⟩ are used to indicate geminated /k/ and /ɡ/, respectively, when they occur before ⟨i⟩ or ⟨e⟩; e.g. occhi /ˈɔkki/ ('eyes'), agghindare /aɡɡinˈdaːre/ ('to dress up').

⟨G⟩ is also used to mark that a following ⟨l⟩ or ⟨n⟩ is palatal, i.e. /ʎ/ (only before ⟨i⟩) or /ɲ/ (everywhere), respectively (this is not true in words derived from Greek, where ⟨gl⟩ is a plain /ɡl/, like in glicine, 'wisteria').

The digraph ⟨sc⟩ is used before ⟨e⟩ and ⟨i⟩ to represent /ʃ/; before other vowels, ⟨sci⟩ is used. Otherwise, ⟨sc⟩ represents /sk/, the ⟨c⟩ of which follows the normal orthographic rules explained above.

Other than in a few Northern Italian dialects, intervocalic /ʎ/, /ɲ/, and /ʃ/ are always geminated and no orthographic distinction is made to indicate this.

S and Z

⟨s⟩ and ⟨z⟩ are ambiguous to voicing.

⟨s⟩ represents a dental sibilant consonant (/s/ or /z/). However, these two phonemes are in complementary distribution everywhere except between two vowels in the same word and, even in such environments, there are very few minimal pairs.

⟨z⟩ represents a dental affricate consonant; either /dz/ (zanzara /dzanˈdzaːra/) or /ts/ (nazione /natˈtsjoːne/), depending on context, though there are few minimal pairs.

Between vowels and/or semivowels (/j/ and /w/), ⟨z⟩ is pronounced as if doubled (/tts/ or /ddz/, e.g. razzo /ˈraddzo/). This can be the case even if a single ⟨z⟩ is used, specifically in words ending in -zione, -zioni, -zia, -zie, and -zio (e.g. vizio /ˈvittsjo/, polizia /politˈtsiːa/).

Other letters

In addition to being used to indicate a hard ⟨c⟩ or ⟨g⟩ before front vowels, ⟨h⟩ is also used to distinguish ho, hai, ha, hanno (present indicative of avere, 'to have') from o ('or'), ai ('to the', m. pl.), a ('to'), anno ('year'); since ⟨h⟩ is always silent, there is no difference in the pronunciation of such words. In foreign loanwords, the h is still silent: hovercraft /ˈɔverkraft/.

The letters J (I lunga 'long I'), K (cappa), W (V doppia or doppia V 'double V'), X (ics) and Y (ipsilon or I greca 'Greek I') are used for loanwords only, with few exceptions.

Diacritics

The acute accent may be used on ⟨e⟩ and ⟨o⟩ to represent close-mid vowels when they are stressed in a position other than the default second-to-last syllable. This use of accents is generally mandatory only in the final syllable; elsewhere, accents are generally found only in dictionaries. Since final ⟨o⟩ is hardly ever close-mid, ⟨ó⟩ is very rarely encountered in written Italian (e.g. metró 'subway', from the original French pronunciation of métro with a final-stressed /o/). The grave accent may be used on ⟨e⟩ and ⟨o⟩ when they represent open-mid vowels. The accents may also be used to differentiate minimal pairs within Italian (for example pèsca 'peach' vs. pésca 'fishing'), but in practice this is limited to didactic texts. In the case of final ⟨i⟩ and ⟨u⟩, both possibilities are encountered. The by far most common option is the grave accent, though this may be due to the rarity of the acute accent to represent stress; the alternative of employing the acute is in practice limited to erudite texts, but can be justified as both vowels are high (as in Catalan). However, since there are no corresponding low (or lax) vowels to contrast with in Italian, both choices are equally acceptable.

The circumflex accent can be used to mark the contraction of two vowels, especially two i's. For example, it can be used to differentiate words like geni ('genes', plural of gene) and genî ('geniuses', plural of genio). This is especially seen in older texts, since two homophones are usually distinguished by the context.