What's the difference between bon and bien?

Bon is an adjective and describes nouns, agreeing with them: une bonne idée. Bien is an adverb and describes verbs, and it never changes: elle travaille bien. It's the same distinction as good and well in English.

Is it c'est bon or c'est bien?

C'est bon judges taste or quality and often means that's tasty or that's enough. C'est bien judges worth and means that's a good thing or well done. Both are correct; they're answering different questions.

Why does bien sometimes follow être like an adjective?

Because bien developed a secondary use meaning fine, decent, or satisfactory. Ce restaurant est bien assesses the place overall, while ce plat est bon assesses the food itself. Bien still never agrees in this use.

Should I say je sens bon or je me sens bien?

They mean different things. Je sens bon means I smell good, with bon as an invariable adverb after a verb of perception. Je me sens bien means I feel well, with the ordinary adverb after a reflexive verb.

What are the comparatives of bon and bien?

Bon becomes meilleur, which agrees: une meilleure idée. Bien becomes mieux, which doesn't: elle chante mieux. Neither takes plus, so plus bon and plus bien are errors in the way more good is in English.

French grammar · Beginner

Bon vs. Bien: Good and Well in French

Written by Camille Laurent, Lead French Curriculum Editor · Reviewed May 2026

Bon is an adjective: it describes a noun and agrees with it, giving bon, bonne, bons, bonnes. Bien is an adverb: it describes a verb and never changes. English uses good and well for the same split, which makes the rule easier than it looks.

C'est un bon restaurant où l'on mange bien.

It's a good restaurant where the food is good.

What it is

The choice is decided by what the word attaches to. A noun takes the adjective bon, which agrees with it. A verb takes the adverb bien, which is invariable. Everything else on this page is a consequence of that one distinction.

un bon dîner (a good dinner) but on a bien dîné (we ate well). Dîner is a noun in the first and a verb in the second.

How to spot it

Find the word being described. If it's a noun, you need bon and you need to make it agree. If it's a verb, an adjective, or another adverb, you need bien.

une bonne raison — a good reason (noun → adjective)
Il travaille bien. — He works well. (verb → adverb)
Elle est bien plus rapide. — She's far faster. (bien intensifying an adverb)
Ce fromage est bon. — This cheese tastes good. (être plus adjective)

Bien has a second life as an adjective after être, where it means fine, decent, or worthwhile rather than tasty or of good quality. That's the one place the rule looks broken.

Bon vs. Bien Quick Reference

Every job the two words do

Word	Role	Agrees?	Example
bon	adjective describing a noun	bon, bonne, bons, bonnes	un bon repas — a good meal
bien	adverb describing a verb	never	Il chante bien. — He sings well.
bien	adjective after être	never	Ce film est bien. — That film is good.
bien	intensifier before an adjective	never	bien content — really pleased
bien des	quantifier	never	bien des gens — a good many people
bon	adverb after certain verbs	invariable	Ça sent bon. — That smells good.
Comparative	meilleur (adj.) / mieux (adv.)	meilleur agrees	C'est meilleur. / Ça va mieux.
Superlative	le meilleur / le mieux	meilleur agrees	la meilleure — the best (f.)

Common Bon vs. Bien Examples in French

The two words in the situations that define them:

Bon: In Front of a Noun

C'est une bonne nouvelle.: That's good news.
Il a de bons résultats.: He has good results.
Bonne chance !: Good luck!
Nous avons passé une bonne soirée.: We had a good evening.

Bon almost always precedes the noun, and because it does, des becomes de in front of it: de bons résultats.

Bien: Attached to a Verb

Tu as bien répondu.: You answered well.
Ça s'est bien passé.: It went well.
Elle parle bien anglais.: She speaks English well.
Dors bien.: Sleep well.

In compound tenses bien goes between the auxiliary and the participle: tu as bien travaillé.

After Être, Both Are Possible

Ce gâteau est bon.: This cake tastes good.
Ce restaurant est bien.: This restaurant is a good place.
Le café est bon ce matin.: The coffee is good this morning.
Ton idée est bien.: Your idea is a good one.

Bon judges the thing's intrinsic quality, often its taste. Bien judges whether it's worthwhile or satisfactory overall.

Bien Meaning Really

Je suis bien content de te voir.: I'm really pleased to see you.
C'est bien mieux comme ça.: That's far better like that.
bien sûr: of course
Il y avait bien du monde.: There really were a lot of people.

This intensifying bien is close to très or beaucoup, but it adds a note of confirmation rather than pure degree.

How to Decide, Every Time

One question resolves most cases. The remaining ones all involve être or a verb of perception.

Ask What the Word Modifies

Bon modifies a noun; bien modifies a verb, an adjective, or another adverb. Everything else follows from that, and the English good and well pair maps onto it almost perfectly.

un bon professeur qui explique bien

a good teacher who explains well

Noun → bon. Verb → bien.

Bon Agrees, Bien Never Does

As an adjective, bon takes the full set of endings: bon, bonne, bons, bonnes. Bien has exactly one form in every sentence it appears in, which removes half the work.

de bonnes intentions

good intentions

Agreement is a bon-only problem.

Bon Usually Comes Before the Noun

Bon belongs to the small group of adjectives that precede their noun, alongside beau, grand, and petit. Placing it after gives a marked, emphatic reading rather than a neutral one.

une bonne réponse

a good answer

bon + noun, in that order.

After Être, Ask What Kind of Judgement You Mean

Bon evaluates the thing itself, its quality or taste. Bien evaluates the experience or the situation. Ce vin est bon is about the wine; ce bar est bien is about whether the place is worth going to.

Le film est bien, mais le livre est meilleur.

The film is good, but the book is better.

Taste and quality → bon. Worth → bien.

Sentir Bon, Se Sentir Bien

Verbs of perception take bon as an invariable adverb: ça sent bon, ça a bon goût. But se sentir, meaning to feel in oneself, takes bien like any other verb. The pair catches out almost everyone.

Le pain sent bon et je me sens bien.

The bread smells good and I feel well.

sentir bon, se sentir bien.

Common Mistakes with Bon vs. Bien

Incorrect: C'est un bien restaurant. — It's a good restaurant.

Correct: C'est un bon restaurant. — It's a good restaurant.

Restaurant is a noun, so it needs the adjective. Bien can follow être but it can never sit in front of a noun.

Incorrect: Elle chante bon. — She sings well.

Correct: Elle chante bien. — She sings well.

Chanter is a verb, so it takes the adverb. Bon after a verb only survives with sentir and a couple of others: ça sent bon.

Incorrect: une bon idée — a good idea

Correct: une bonne idée — a good idea

Idée is feminine, and bon is an adjective, so it agrees. The n doubles before the e, giving bonne with a nasal that disappears in speech.

Incorrect: Je me sens bon. — I feel well.

Correct: Je me sens bien. — I feel well.

Se sentir takes the adverb like any other verb. Je sens bon does exist, but it means I smell good, which is a very different statement.

Bien's Extra Jobs

Bien does far more work than bon, and three of its uses have nothing to do with the adverb of manner.

Bien as an intensifier

In front of an adjective, an adverb, or a quantity, bien means really or considerably. It's stronger than assez and warmer than très.

bien sûr: of course
C'est bien trop cher.: That's far too expensive.
Elle est bien meilleure que moi.: She's much better than me.
bien des fois: many a time

Bien des is a quantifier meaning a good many, and it takes no de after it: bien des gens, not bien de gens.

Bien as an adjective and as a noun

After être, bien behaves like an invariable adjective meaning fine, decent, or good-looking. With an article it becomes a noun meaning good, or in the plural, possessions.

Ces gens sont très bien.: Those people are thoroughly decent.
le bien et le mal: good and evil
Il a vendu tous ses biens.: He sold all his possessions.
C'est pour ton bien.: It's for your own good.

Even as an adjective, bien never agrees: elles sont bien, not elles sont biennes.

Fixed phrases on both sides

Each word anchors a set of expressions where the choice is already made and can't be reasoned about.

bon marché: cheap
de bonne heure: early
bien entendu: naturally, of course
Eh bien…: Well then…
bien que ce soit tard: although it's late

Bien que means although and always takes the subjunctive: bien qu'il soit fatigué.

Bon vs. Bien FAQs

What's the difference between bon and bien?: Bon is an adjective and describes nouns, agreeing with them: une bonne idée. Bien is an adverb and describes verbs, and it never changes: elle travaille bien. It's the same distinction as good and well in English.
Is it c'est bon or c'est bien?: C'est bon judges taste or quality and often means that's tasty or that's enough. C'est bien judges worth and means that's a good thing or well done. Both are correct; they're answering different questions.
Why does bien sometimes follow être like an adjective?: Because bien developed a secondary use meaning fine, decent, or satisfactory. Ce restaurant est bien assesses the place overall, while ce plat est bon assesses the food itself. Bien still never agrees in this use.
Should I say je sens bon or je me sens bien?: They mean different things. Je sens bon means I smell good, with bon as an invariable adverb after a verb of perception. Je me sens bien means I feel well, with the ordinary adverb after a reflexive verb.
What are the comparatives of bon and bien?: Bon becomes meilleur, which agrees: une meilleure idée. Bien becomes mieux, which doesn't: elle chante mieux. Neither takes plus, so plus bon and plus bien are errors in the way more good is in English.