Liaison is a phonetic phenomenon whereby a normally silent final consonant of a word is pronounced when followed by a word beginning with a vowel. The term pertains especially to the French language. See also sandhi and elision.

In French, consonants are normally silent at the end of a word. For example, both s and t are silent in est. However, if the following word starts with a vowel, the 't' is pronounced and linked to the vowel.

• Elle est canadienne. (She is Canadian.)
• Elle est [t]américaine. (She is American.)

The same process also happens to nasal vowels, where they are denasalized and the n is linked to the next vowel.

• mon père (my father)
• mon [n]ami (my friend)

Liaison is not used all the time. There are cases where it is either mandatory, optional, or grammatically impossible.