Highway to the Liaison Zone

or, How to Survive the Danger of Liaisons

A reader wrote to us recently with a very good question:

“I would really like to understand when to use liaisons and when not to. When is it obligatory, when is it optional, and when is it forbidden?”

Though I am an incorrigible linguist, I am going to do my absolute best to not nerd out too hard in the following explanation.

This post will:

  1. Define la liaison and distinguish it from similar processes
  2. Bring up a few necessary background details
  3. Give three lists (not 100% comprehensive, but pretty close) of when la liaison is obligatory, optional, and forbidden (respectively)

1. What it is, and what it isn’t

The first thing to keep in mind is that French really, really doesn’t like two vowels to touch. They need some personal space, and that personal space is ideally made of consonants. To avoid awkward physical contact, there are a few major strategies you need to know and use:

la liaison (English: liaison) – Say we have two words next to each other in a sentence. The first one ends in a vowel, but is written with a silent consonant. The second begins with a vowel (although the written form may begin with a silent <h>, as in homme). Liaison takes the first word’s silent, written consonant and turns it into a spoken consonant, thus sparing the two vowels from the horror of having to be pronounced one directly after the other.

For example: The word les ends in a vowel, since the s at the end is silent. The word amis begins with a vowel. When they’re combined, we prevent disaster by taking the silent, written-only s and giving it a spoken sound (still spelled s, but it will sound like a z). This post will mark where liaison occurs using the symbol ‿ between words: les‿ amis.

Remember: liaison adds a sound between two words that wasn’t there when those words were on their own.

l’enchainement (English: linking) – This is very similar to la liaison, but the key difference is that the first of two spoken words in this case ends in a pronounced consonant, while the second begins with a vowel. The exact same number of sounds are pronounced when the two words are spoken together as when they were on their own. So what changes? The sounds are re-distributed within syllables. All the nerdy things I want to tell you about syllables will have to wait for another day.

For now, consider the rhythm of the following words when they appear on their own:

 il ‘he’… arrive ‘arrives’… à ‘at’ seize ‘sixteen’… heures ‘hours’

But when you combine them into a complete sentence, the sounds link up in ways that don’t care about the word boundaries you see written on a page. Instead, you’ll find that syllables want to start with a consonant, and will even steal the consonant from the end of the previous word if there’s one available. Try saying this sentence out loud by first reading the normal written form, and then looking at the line below it where I’ve typed an X under each syllable. Now look at the version below that where I’ve separated the spoken syllables using a <.>.

Il arrive à seize heures (‘He’ll get here at 4:00 PM’)
X X X     X   X       X

i .la.rri .va .sei.zheures
X X X     X   X       X

l’élision (English: elision) – While la liaison adds a sound that wasn’t there and l’enchainement keeps the same number of total sounds, l’élision deletes a sound in order to keep vowels from touching. That’s right: the vowels find the prospect of physical contact so mortifying that one of them decides to cease to exist. That’s intense.

Elision happens most often with the singular definite articles le and lale + homme = l’homme; la + amie = l’amie. You’ll also see it when si ‘if’ goes before il or ils (s’il, s’ils) but not before elle or really anything else.

2. Some extra details

2.1. Spoken versus written French

I have to remind you of the huge difference between spoken and written French and what it means for us here. French doesn’t want vowels to touch in the spoken language, so the written language’s silent letters don’t automatically help anyone. Because this distinction is so important, I’ll sometimes specify which I mean by using different types of brackets:

Written language in angle brackets, <comme ça>.

Spoken language pronunciations in square brackets and using the International Phonetic Alphabet (IPA), [kɔm sa]. If you don’t know the IPA yet…you should change that as soon as possible. It’s so incredibly useful to learning and improving pronunciation in any language. I’ll probably end up writing a post on that next, in fact. For now, this page is a decent introduction.

2.2. Levels of formality

French is a living language, meaning real humans use it, meaning that there’s a spectrum from formal to informal language. This is directly related to the topic at hand, because the more formal the French, the more liaison you have to use, and the more people will make the mockery of you if you use it where it’s forbidden.

If you’re a non-native speaker, it’s usually best to avoid speaking in the most or the least formal ways. This post generally aims for the sort of level you might use in the workplace, but the kind where you’re speaking with co-workers, not with your scary boss who wears a top hat and a monocle.

2.3. Particularities of pronunciation in la liaison

When you take a silent letter and turn it into a pronounced sound for the purposes of liaison, that letter might not be pronounced the way it usually is in written French. Here are some of the main weirdnesses:

<s> and <x>  → [z]               as in    des‿ idées [de.z‿i.de]

                                                 or        six‿ heures [si.z‿œʁ]

<d>                 → [t]                as in    grand‿ arbre [gʁɑ̃.t‿aʁ.bʁə]

<g>                  → [k] (rare)   as in    sang‿ impur [sɑ̃.k‿ɛ̃pyʁ] (This is the only example I could find of it, and it’s falling out of use. Good riddance, racist/classist expressions)

<f>                  → [v]                as in   neuf ans [nœ.v‿ɑ̃]

Alright. Now, at long last, I will answer the actual question.

3. When you must, when you may, and when you mustn’t use liaison

Notation reminders:

The symbol shows where the liaison border occurs or can occur.

The symbol | shows where a liaison cannot occur.

3.1. When you must (la liaison obligatoire )

Between a determiner (a category including articles, possessive adjectives, and demonstratives) and its associated noun

e.g. un an, les amis, ton avis, vos idées, ces ennemis

When an adjective precedes the noun it describes

e.g. un grand homme

Between a subject pronoun and its associated verb

e.g. nous aimons

Also between the verb and its subject pronoun when they’re inverted

e.g. vont-‿ils à la fête?

When an imperative verb precedes y or en

e.g. vas-‿y!; prends-‿en!

In certain compound words and fixed expressions:

e.g. c’est à dire, de temps en temps

3.2. When you may, but don’t have to (la liaison facultative )

Often between conjugated forms of être or avoir and their complement (this can be a noun or pronoun object, or an adjective)

e.g. elle est intelligente; ils en ont assez

Also between conjugated être and avoir and the past participle of the main verb, when they act as auxiliary verb to it

e.g. ils sont allés

Between a preposition, especially a monosyllabic one, and its complement

e.g. sans espoir, dans une heure

When an adverb that modifies the word directly following it

e.g. bien amusé, très heureux

Note: with beaucoup, liaison sounds pretty snooty. For example, in Nous l’avons beaucoup(‿) aimé, you’re probably better off not pronouncing the final <p> unless you’re wearing a monocle at that very moment.

Sometimes between a verb (that isn’t être or avoir) and its complement (more common for direct objects than indirect ones)

e.g. il prend un café

Sometimes between a plural noun and its following associated adjective (but NOT a singular noun before an adjective; see below)

e.g. des soldats américains (but un soldat | américain)

3.3. When you mustn’t (la liaison interdite )

When a singular noun precedes the adjective that describes it

e.g. un soldat | américain

Between et and anything

e.g. elle est charmante et | intelligente

Between anything and a word beginning with an h aspiré (look in a dictionary to find out whether your <h> is silent or aspiré…unfortunately, that’s the only real way to tell)

e.g. ce ne sont pas des | haricots

Between anything and un (when it’s a number, not an article), huit (even though it doesn’t begin with h aspiré) or onze

e.g. ils en ont | huit

…except: the phrase les uns (et) les autres

Between anything and a word beginning with a glide ([w], [j], [ɥ])

e.g. mon | yaourt; des non et des | oui

…except: des yeux

In certain compound words and fixed expressions:

e.g. nez | à nez


Whew. That was a lot. I hope this article helps as you learn and improve in French pronunciation. Don’t be discouraged if it takes a long time to apply these rules; a lot of this is considered intermediate or advanced-level stuff. And if you have more questions about it, don’t hesitate to contact us.