In French, elision () is the suppression of a final unstressed vowel (usually ) immediately before another word beginning with a vowel or a silent . The term also refers to the orthographic convention by which the deletion of a vowel is reflected in writing, and indicated with an apostrophe.
Written French
In written French, elision (both phonetic and orthographic) is obligatory for the following words: the definite articles and ("the boy"), ("the girl") + → ("the tree"), + → ("the church") the subject pronouns and (when they occur before the verb) . ("I sleep") . ("That would be great.") . ("I slept.") . ("It was great.") but: ? ("Did I imagine?"), ? ("Is that useful?") the object pronouns , , , , and (when they occur before the verb) . ("Jean shaves himself, sees her, phones me.") . ("Jean shaved himself, saw her, phoned me.") but: . ("Look at him one more time.") the object pronouns when they occur after an imperative verb and before the pronoun or : . ("Put it, give me them, scram.") . ("Put it there, give me some, leave.") the negative marker . ("She isn't talking anymore.") . ("She won't stop talking.") the preposition . ("Jean's father just left.") . ("Albert's father just arrived.") (which has many different functions) . ("What are you saying? That Jean does nothing but eat.") . ("What did you say? That we only had one more week left.") The conjunction plus the pronouns and ("if she likes cats") ("if he/they like cats")
Elision is indicated in the spelling of some compound words, such as "peninsula", "today", and "someone".
At the beginnings of words, the aspirated h forbids elision. Example: . The mute h, however, requires elision. Example: . Both types of "h" are silent regardless.
Informal French Elision of the second-person singular subject pronoun , before the verbs beginning with a vowel or mute h (silent h), and of the particle of negation , is very common in informal speech, but is avoided in careful speech and never used in formal writing: . "You decided to visit them, you went to see the film, you were not there, I don't know." (careful speech) T'as décidé de lui rendre visite, t'es allé voir le film, t'étais pas là, je sais pas. (informal speech)
See also Liaison (French) Elision — broader discussion of elision in other languages
References Maurice Grevisse, Le Bon Usage, 14th edition by André Goosse, de Boeck, 2007,