Les Voyelles Nasales: an, en, in, un, on

Nasal vowels are one of the defining features of French phonology and one of the major obstacles for English speakers. They are produced by lowering the velum so that air resonates simultaneously through the mouth and the nose, and — critically — the n or m that appears in their spelling is not pronounced as a separate consonant. The vowel itself carries the nasal resonance. This page lays out the three or four nasal vowels of standard French, the spelling rules that predict when a vowel sequence will be nasal, and the contexts where a vowel followed by n or m stays oral. Master this system and you will stop saying bon with a hard /n/ at the end — the single most common pronunciation error among beginners.

What a nasal vowel actually is

In a typical English vowel, all the air passes through the mouth. The velum (soft palate) is raised, sealing off the nasal cavity. When the velum lowers, the nasal passage opens, and air resonates through both pathways simultaneously. The resulting vowel has a distinctive humming quality.

English has nasalised vowels in some accents (the vowel of can before n gets some nasalisation in many dialects), but it does not have phonemic nasal vowels — vowels where nasality is the only feature distinguishing two words. French does. Beau /bo/ and bon /bɔ̃/ differ only in nasality; paix /pɛ/ and pain /pɛ̃/ differ only in nasality. The contrast carries meaning.

The most important thing to internalise from the start is that the n or m is not pronounced as a consonant. When you see bon, do not say /bon/ with a separate /n/ at the end. The word is two segments: /b/ + /ɔ̃/. The nasality lives inside the vowel, and the n in the spelling is a graphic indicator of nasality, not a pronounced sound.

The four nasal vowels

Standard French has four nasal vowels in the traditional analysis. Most contemporary metropolitan speakers merge two of them, producing a three-vowel system. We will cover all four; you will hear three in practice in most of France.

The fourth nasal /œ̃/ is in retreat. In Paris and northern France, speakers under fifty largely merge it with /ɛ̃/, so un and brin, brun and brin, parfum and (hypothetical) parfin all sound alike. Southern French, Belgian French, and Quebec French preserve the distinction. Both pronunciations are accepted as standard; teaching materials still distinguish four nasals in writing, but you will hear three in most contemporary recordings.

Examples of all four:

The last sentence packs seven nasal vowels: cinquante /sɛ̃.kɑ̃t/ (two — /ɛ̃/ then /ɑ̃/) + cinq /sɛ̃k/ (/ɛ̃/) + passants /pa.sɑ̃/ (/ɑ̃/) + attendent /a.tɑ̃d/ (/ɑ̃/) + train /tʁɛ̃/ (/ɛ̃/) + Lyon /ljɔ̃/ (/ɔ̃/). Hearing each as a single nasalised vowel rather than a vowel-plus-/n/ sequence is the listening skill to develop.

The /ɛ̃/ vowel: vin, pain, fin

The vowel /ɛ̃/ is a nasalised version of /ɛ/ (the e of English bed). Lips are slightly spread, tongue is forward, and the velum is lowered. The result is a tense, somewhat sharp nasal vowel.

Spellings: in (vin, fin, matin, jardin), im (impossible, important — when followed by p or b), ain (pain, main, certain), ein (plein, peinture), yn (synthèse — rare), ym (sympa, symptôme).

The /ɛ̃/ contrasts with /ɛ/ purely on nasality: paix /pɛ/ vs pain /pɛ̃/, fait /fɛ/ vs fin /fɛ̃/. English speakers who fail to nasalise will collapse this distinction.

The /ɑ̃/ vowel: an, sans, dans, comment

The vowel /ɑ̃/ is a nasalised version of /ɑ/ (the a of English father, somewhat darker). The mouth is more open than for /ɛ̃/, the lips are neutral, and the tongue is in the back of the mouth.

Spellings: an (an, sans, dans, gant), am (chambre, jambe, ample, lampe — when followed by p or b), en (comment, présent, en, prendre), em (temps, ensemble, emporter, embarrasser).

A spelling-pronunciation note: the digraphs en and em most commonly produce /ɑ̃/, but in a handful of words and in prefixes they produce /ɛ̃/. The most common cases are examen (/ɛɡzamɛ̃/), bien (/bjɛ̃/), mien (/mjɛ̃/), and the family of -ien nouns/adjectives (Italien, Canadien, ancien, lien). The conditioning factor is usually a preceding /j/ glide.

This sentence has /ɛ̃/ in ancien and italien (both -ien) and /ɑ̃/ in nothing else. The en of revenu is oral /ə/ + /ny/, not nasal at all. Spelling alone does not disambiguate; you have to learn the -ien exception.

The /ɔ̃/ vowel: bon, mon, on, nom

The vowel /ɔ̃/ is a nasalised version of /o/ or /ɔ/. Lips are rounded, tongue is back, and the velum is lowered. Of the four nasal vowels, /ɔ̃/ is often described as the most distinctive to the English ear.

Spellings: on (bon, mon, ton, son, on, non), om (ombre, nombre, tomber, comble — when followed by b or, more rarely, p).

The /ɔ̃/ is the easiest of the nasal vowels to identify because the lip rounding makes the visual cue strong. Watch a French speaker say bon and you will see clearly that the lips never close to form /n/ — the rounding is held throughout the vowel, and the word ends with the lips still rounded.

The /œ̃/ vowel: un, parfum, lundi

The vowel /œ̃/ is a nasalised /œ/, with the lip rounding of /œ/ (front rounded vowel) plus nasalisation. In conservative speech it is distinct from /ɛ̃/; in modern Parisian speech it is generally merged with /ɛ̃/.

Spellings: un (un, brun, lundi, chacun, aucun), um (parfum, humble — when followed by b or, in a few words, no following consonant).

In the merged-Parisian pronunciation, lundi /lœ̃di/ becomes /lɛ̃di/, un becomes homophonous with hein (/ɛ̃/), parfum becomes /paʁfɛ̃/. Both pronunciations are widely accepted; TV news anchors trend toward /ɛ̃/ for both, while older speakers and the conservative Académie pronunciation distinguish them. As a learner, you can pick either; the merged version is closer to most contemporary spoken French.

The crucial spelling rule: when nasality fires, when it doesn't

A vowel followed by n or m nasalises only when the n or m is at the end of the syllable — that is, when no vowel follows in the same word. When n or m is followed by another vowel, it begins a new syllable, the n/m is fully pronounced, and the preceding vowel stays oral.

The rule has two practical halves:

Single n/m at end of syllable → nasal vowel, n/m silent.

Here vin and dans have a single n at end of syllable; both nasalise; the n is silent.

Single n/m followed by vowel → oral vowel, n/m fully pronounced.

Here année has nn (the doubled consonant) followed by a vowel: oral /a/ + pronounced /n/ + /e/. Ancienne has the same: nasal /ɑ̃/ in anc- (n at end of syllable), then -ienne with oral /jɛn/.

Doubled nn or mm → oral vowel, n/m pronounced once.

Here femme — note the irregular pronunciation /fam/ — has mm with a following vowel; the result is oral /a/ + /m/ + silent e.

The pattern can be summarised: n or m nasalises a preceding vowel only if it is alone (not doubled) and at the end of its syllable. Otherwise the vowel stays oral and the consonant is pronounced.

The trap: same letters, different sounds

The same letter sequence can produce both nasal and oral pronunciations across related words. This is one of the systematic challenges of French pronunciation.

• an (year) /ɑ̃/ vs anne (Anne, name) /an/ vs année (year) /a/+/n/+/e/.
• bon (good, m. sg.) /bɔ̃/ vs bonne (good, f. sg.) /bɔn/.
• plein (full, m. sg.) /plɛ̃/ vs pleine (full, f. sg.) /plɛn/.
• un (one, m. sg.) /œ̃/ or /ɛ̃/ vs une (one, f. sg.) /yn/.

The pattern is consistent: when feminine agreement adds an e to a masculine form, that e opens a syllable and the previously-nasalised vowel becomes oral plus a pronounced /n/. So bon → bonne changes from one nasal segment to two oral segments: /bɔ̃/ → /bɔn/. Plein → pleine: /plɛ̃/ → /plɛn/.

This is why French masculine and feminine adjective pairs often sound dramatically different even though they look like minor spelling tweaks. Italien is /italjɛ̃/, but italienne is /italjɛn/.

The minimal-pair contrast across these two sentences is striking. Copain /kɔpɛ̃/ vs copine /kɔpin/ (note: even the vowel quality changes: /ɛ̃/ → /i/ here, because the spelling in nasalises but ine gives /in/). Italien /italjɛ̃/ vs italienne /italjɛn/. Bon /bɔ̃/ vs bonne /bɔn/. The masculine forms are nasal-vowel; the feminine forms are oral-vowel-plus-/n/.

Listening practice: identifying the nasal

A classic exercise to develop nasal-vowel ear: listen for whether the speaker's mouth closes for /n/ or /m/ at the end of a word. If it does — if you can see the lips coming together for /m/ or the tongue rising for /n/ — the consonant is being pronounced and the vowel is oral. If the mouth stays open and you hear a humming quality through the vowel, the vowel is nasalised and the consonant is silent.

Try this with the following pairs. The top word is nasal; the bottom is oral.

Each pair contains the masculine form (nasal vowel, silent consonant) and the feminine form (oral vowel, pronounced consonant). Practising these pairs is the fastest route to internalising the system.

Comparison with English

English has nasalised vowels in some dialects, especially before nasal consonants — the vowel of can't in American English is mildly nasal — but the nasalisation is allophonic, not contrastive. It does not distinguish words. French nasal vowels are phonemic: they distinguish paix /pɛ/ from pain /pɛ̃/, beau /bo/ from bon /bɔ̃/.

The other major divergence is that English speakers expect the n or m in spelling to be pronounced. Bon looks like bone without the e — and English speakers naturally read bone with a pronounced /n/. French does not pronounce that n. Retraining the eye to read vowel + n/m as a single nasal vowel is the perceptual shift.

A useful comparison: Portuguese has nasal vowels too, written variously with tilde (pão) or with a following nasal consonant (bem). Portuguese learners of French have an easier time than English learners. Spanish has no nasal vowels at all; Spanish learners face the same retraining as English speakers.

Common Mistakes

The fourth and sixth errors are the most consequential. In the fourth, the masculine-feminine distinction collapses if the speaker treats bon and bonne as having the same final consonant — French listeners will not be able to tell which form is meant, and gender agreement information is lost. In the sixth, the vowel-following-/n/ rule is so consistent that mispronouncing it makes the speaker sound robotic to a native ear.

Where to go next

Now that you have the nasal-vowel system in place, the natural next steps are the related phonological pages:

• Silent final consonants — pronunciation/silent-final-consonants — the broader pattern of which consonants are silent at the end of words.
• Liaison — what happens when a normally silent consonant resurrects before a vowel.
• Elision and contraction — pronunciation/elision-and-contraction — how short grammatical words drop their final vowel.
• The uvular R — pronunciation/uvular-r — French's signature consonant.
• H muet vs h aspiré — pronunciation/aspirated-vs-silent-h — the two silent h types.

A short daily routine of pronouncing minimal pairs (bon/bonne, vin/vine, plein/pleine) will build the nasal-vowel reflex faster than any other exercise. After two or three weeks of conscious practice, the distinction will start to feel automatic.

Key takeaways

French has three or four nasal vowels — /ɛ̃/, /ɑ̃/, /ɔ̃/, and /œ̃/ (often merged with /ɛ̃/ in modern speech). The defining feature of a nasal vowel is that the n or m in the spelling is silent: the nasal resonance lives in the vowel itself, not in a following consonant. The spelling rule is mechanical: a vowel + single n/m nasalises only when the n/m closes the syllable; doubled nn/mm and n/m followed by a vowel keep the vowel oral and pronounce the consonant. Masculine-feminine adjective pairs typically alternate between nasal-vowel masculines (bon, plein, italien) and oral-vowel-plus-/n/ feminines (bonne, pleine, italienne) because the added e opens a new syllable. Internalising these patterns transforms what feels like a baffling reading challenge into a small set of mechanical rules — and it is the single most important step toward sounding French rather than foreign.