In phonology, syncope (ˈsɪŋkəpi; from ) is the loss of one or more sounds from the interior of a word, especially the loss of an unstressed vowel. It is found in both synchronic and diachronic analyses of languages. Its opposite, whereby sounds are added, is epenthesis.
Synchronic analysis studies linguistic phenomena at one moment of a language's history, usually the present, in contrast to diachronic analysis, which studies a language's states and the patterns of change across a historical timeframe. In modern languages, syncope occurs in inflection, poetry, and informal speech.
In languages such as Irish and Hebrew, the process of inflection can cause syncope:
In some verbs
imir (to play) should become *imirím (I play). However, the addition of the -ím causes syncope and the second-last syllable vowel i is lost so imirim becomes imrím.
כָּתַב (katav), (he) wrote, becomes כָּתְבוּ (katvu), (they) wrote, when the third-person plural ending ־וּ (-u) is added.
In some nouns
inis (island) should become *inise in the genitive case. However, instead of *Baile na hInise, road signs say, Baile na hInse (the town of the island). Once again, there is the loss of the second i.
If the present root form in Irish is the result of diachronic syncope, synchronic syncope for inflection is prevented.
Sounds may be removed from the interior of a word as a rhetorical or poetic device: for embellishment or for the sake of the meter.
Latin commōverat > poetic commōrat ("he had moved")
English hastening > poetic hast'ning
English heaven > poetic heav'n
English over > poetic o'er
English ever > poetic e'er, often confused with ere ("before")
Various sorts of colloquial reductions might be called "syncope" or "compression".
Contractions in English such as "didn't" or "can't" are typically cases of syncope.