Liaisons in French: when to link, when to avoid

Liaisons make French sound like a continuous ribbon. Lovely when they fall just right, awkward when they pop up in the wrong place. Good news: they follow three simple families that are easy to remember.

The principle in one minute

A liaison is the pronunciation of a normally silent final consonant before a word that begins with a vowel or a silent h. It avoids the clash between two vowels and smooths out the spoken chain. Example: "les amis" → "les‿amis" (/le.z‿a.mi/). This is not the same as linking, which involves reintroducing a consonant that has already been pronounced; here we reactivate a latent consonant. The norm distinguishes three types — mandatory, optional, and prohibited — a detailed classification in the grammatical tradition according to the Académie française.

Mandatory liaisons

They almost always occur, even in fast speech. Missing them sounds strange to a native ear.

• Determiner + noun or adjective: « the‿friends » (/le.z‿a.mi/), « my‿children » (/me.z‿ɑ̃.fɑ̃/).
• Clitic pronouns + verb: « you‿have » (/vu.z‿a.ve/), “they‿are” (/il.z‿ɔ̃/).
• Short adverb + adjective/verb: “very‿useful” (/tʁɛ.z‿y.til/), “beloved” (/bjɛ̃.n‿e.me/).
• Adjective before the noun (frequentatives): “a little‿child” (/œ̃ pə.ti.t‿ɑ̃.fɑ̃/), “a good‿friend” (/œ̃ bɔ̃.n‿a.mi/).

Optional liaisons

They depend on the register(formal vs. informal), the flow, and the desired effect. They are more willingly performed in reading aloud, in theater, or in a formal context.

• After a conjugated verb: "they arrive‿at eight o'clock" (/il.za.ʁiv‿a ɥit‿œʁ/) — careful; in rapid conversation, one may not link.
• After adverbs or polysyllabic words: "often‿useful" (/su.vɑ̃.n‿y.til/), "really‿important" (/vʁɛ.mɑ̃.n‿ɛ̃.pɔʁ.tɑ̃/).
• Between plural noun and adjective: "adorable‿children" (/de.z‿ɑ̃.fɑ̃.n‿a.dɔ.ʁabl/) in careful style; in everyday style, one may drop it.
• After "when", "whose", "at", "very" except in obvious cases — the decision depends on the rhythm and clarity sought.

Prohibited links and the trap of the aspirated h

Certain links clearly clash with usage. Classical traps: after "and" ("and a" without linking), after a strongly accented singular noun, after a proper noun, and especially before the words with aspirated h.These words refuse linking and elision: "the bean" (not "the bean"), thus no linking: "the beans" (/le a.ʁi.ko/). Conversely, with an silent h, we connect: « les‿hommes » (/le.z‿ɔm/).

• « et un »: no liaison (/e œ̃/). « et avec » same.
• After « pas », common usage avoids: « pas hier » (/pa jɛʁ/). In very careful diction, you might hear the liaison, but it’s marked.
• Some frequent aspirated h's: haricot, héros, hibou, hache, haine, honte. We say « le héros », « des haricots », never elision or liaison.

My experience

At first, I forced liaisons everywhere, especially after « pas » and « et ». One day, while listening to myself, I heard that little extra « z » in « pas‿ici ». Since then, I note the words with aspirated h that trip me up (haricot, héros…) and I read mini-texts aloud, varying the register: one version « conversational », one version « diction » to feel when the liaison adds clarity rather than a sound tic.

How to train yourself

Take 6–8 phrases and record yourself in two versions: without optional liaison, then with. Compare the fluidity and understanding. If phonetics helps you, you can display the IPA word by word in Discus (generated on demand) or activate the global display preference from the module IPA. To work on both listening and spelling at the same time, the dictations from Discus validate character by character — perfect for spotting where the liaison is heard but not written.

To go further

From a phonological perspective, the liaison falls under "external sandhi": a latent consonant (often orthographic) is realized before the following vocalic segment and is resyllabified: "les amis" /le.z‿a.mi/ where z becomes the onset of a syllable. Historically, many of these consonants were pronounced in Old/Middle French and have been neutralized in absolute final position, but maintained in liaison contexts. The famous -s plural becomes [z], -t becomes [t] (see "does he" : t euphonious analog created to avoid hiatus), -n reappears in pairs like "good‿friend" /bɔ̃.n‿a.mi/. Diaphasic variation is documented: the formal register multiplies optional liaisons while the familiar avoids them to maintain a more relaxed syllabic rhythm. To continue exploring the current norm and its nuances of usage, visit the dedicated language page: French.