In French, elision (élision) is the suppression of a final unstressed vowel (usually /ə/) immediately before another word beginning with a vowel or a silent ⟨h⟩.
The term also refers to the orthographic convention by which the deletion of a vowel is reflected in writing, and indicated with an apostrophe.
In written French, elision (both phonetic and orthographic) is obligatory for the following words: Elision is indicated in the spelling of some compound words, such as presqu'île "peninsula", aujourd'hui "today", and quelqu'un "someone".
At the beginnings of words, the aspirated h forbids elision.
Elision of the second-person singular subject pronoun tu, before the verbs beginning with a vowel or mute h (silent h), and of the particle of negation ne, is very common in informal speech, but is avoided in careful speech and never used in formal writing:[citation needed]