Syllabification ( /sᵻˈlæbᵻfᵻˈkeɪʃən/ si-LAB-i-fi-KAY-shən) or syllabication (/sᵻˈlæbᵻˈkeɪʃən/ si-LAB-i-KAY-shən) is the separation of a word into syllables, whether spoken or written.
The written separation is usually marked by a hyphen when using English orthography (e.g., syl-la-ble) and with a period when transcribing in the International Phonetic Alphabet (IPA) (e.g., [ˈsɪl.ə.bᵊɫ]). For presentation purposes, typographers may use an interpunct (Unicode character U+00B7, e.g., syl·la·ble), or a special-purpose "hyphenation point" (U+2027, e.g., syl‧la‧ble). Occasionally, but unlikely, a space is used (e.g., syl la ble).
At the end of a line, a word is separated in writing into parts, conventionally called "syllables", if it does not fit the line and if moving it to the next line would make the first line much shorter than the others. This can be a particular problem with very long words, and with narrow columns in newspapers. Word processing has automated the process of justification, making syllabification of shorter words often unnecessary.
In some languages, the spoken syllables are also the basis of syllabification in writing. However, possibly due to the weak correspondence between sounds and letters in the spelling of modern English, written syllabification in English is based mostly on etymological or morphological instead of phonetic principles. For example, it is not possible to syllabify "learning" as lear-ning according to the correct syllabification of the living language. Seeing only lear- at the end of a line might mislead the reader into pronouncing the word incorrectly, as the digraph ea can hold many different values. The history of English orthography accounts for such phenomena.
English written syllabification therefore deals with a concept of "syllable" that does not correspond to the linguistic concept of a phonological (as opposed to morphological) unit.
As a result, even most native English speakers are unable to syllabify words according to established rules without consulting a dictionary or using a word processor. Schools usually do not provide much more advice on the topic than to consult a dictionary. In addition, there are differences between British and US syllabification and even between dictionaries of the same English variety.
In Finnish, Italian, Portuguese and other nearly phonemically spelled languages, writers can in principle correctly syllabify any existing or newly created word using only general rules. In Finland, children are first taught to hyphenate every word until they produce the correct syllabification reliably, after which the hyphens can be omitted.