French Liaison Rules: Obligatory, Optional and Forbidden

In French, many final consonants are silent, but some of them come back to life when the next word starts with a vowel. Les is [le], but les amis is [le.za.mi]. This is liaison. Getting it right is partly about sounding natural and partly about being understood: the liaison consonant often carries the plural, as in ils ont (they have, [il.zɔ̃]) vs ils sont (they are, [il.sɔ̃]).

What sound the consonant makes

The liaison consonant is not always pronounced the way it is written:

The liaison consonant is pronounced as the first sound of the next syllable: les amis is lé-za-mi, not léz-a-mi. With a nasal vowel, the vowel usually stays nasal: mon ami is [mɔ̃.na.mi]. The exceptions are the adjectives bon, ancien, plein and moyen, which denasalise: bon ami is [bɔ.na.mi].

Obligatory liaisons

These are made by virtually all speakers in all styles. Skipping them sounds like a mistake.

1. Determiner + noun or adjective: les enfants, des amis, un homme, mon ami, ces arbres, deux ans, quels amis.
2. Adjective + noun (adjective before the noun): petit enfant, grands hommes, bon anniversaire.
3. Pronoun + verb, and verb + pronoun: nous avons, vous êtes, ils ont, elles arrivent, on est, allez-y, prend-il.
4. After a one-syllable preposition or adverb: dans un, chez eux, en été, très important, plus âgé.
5. Fixed expressions: de temps en temps, tout à fait, les États-Unis, avant-hier, Comment allez-vous ?

Forbidden liaisons

Making these is an error, not a sign of formality:

1. After et: un homme et | une femme. Never "et-t-une".
2. After a singular noun: un étudiant | anglais, le temps | est beau.
3. Before an aspirated h (h aspiré, see below): les | héros, des | haricots, en | haut.
4. After a proper name: Jean | est là.
5. After an inverted subject pronoun: Ont-ils | eu..., Vont-elles | arriver.
6. Before oui, onze and onzième: les | onze joueurs, mais | oui.

The aspirated h

French h is never pronounced. But some words beginning with h, mostly of Germanic origin, behave as if they began with a consonant: they block liaison and elision. These are marked with an asterisk or apostrophe in dictionaries. Compare:

Useful aspirated-h words to learn: haricot, héros, hibou, hache, haut, honte, hasard, huit, hors, hockey, hamburger, Hollande. Note that héroïne has a mute h, even though héros does not.

Optional liaisons

Between these extremes lie the optional liaisons, which depend on style. They are common in speeches, news reading and poetry, and rarer in conversation:

• After plural nouns: des enfants‿adorables (formal) or des enfants | adorables.
• After forms of être: c'est‿un ami is very common; ils sont‿arrivés is formal.
• After multi-syllable prepositions and adverbs: pendant‿un an, toujours‿aimé.
• After pas: pas‿encore, pas‿un.

A good strategy for learners is to make all the obligatory liaisons, avoid all the forbidden ones, and use optional liaisons after c'est and pas, which are frequent in everyday speech.

Frequently asked questions

What is the difference between liaison and enchaînement?

Enchaînement links a consonant that is always pronounced to the next vowel: elle arrive becomes e-la-rrive. Liaison makes a normally silent consonant audible before a vowel: les (silent s) becomes lez in les amis.

Is liaison after "et" possible?

Never. Et never links: un homme et une femme has no t sound. Saying "et-t-une" is a well-known error.

Do French speakers make all optional liaisons?

No. Corpus studies show that optional liaisons are made much more often in formal speech, reading aloud and by older or more educated speakers. In conversation, most optional liaisons are skipped.

Sources and further reading

• Tranel, B. (1987). The Sounds of French: An Introduction, chapter 11: Liaison. Cambridge University Press.
• Encrevé, P. (1988). La liaison avec et sans enchaînement: phonologie tridimensionnelle et usages du français. Seuil.
• Durand, J. and Lyche, C. (2008). French liaison in the light of corpus data. Journal of French Language Studies, 18(1), 33–66.

Read More in This Topic

• French Silent Letters: Which Final Consonants to Pronounce
• French Rhythm and Intonation: Why French Has No Word Stress
• French Pronunciation for English Speakers: A Complete Sound Guide

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