Bon or Bien: the French Words for Good and Well

English has the same pair, good and well, and the same rule: good is an adjective, well is an adverb. The difference is that English no longer enforces it. Nobody is misunderstood for saying I speak French good, and half the people around you say I am doing good. French enforces it, and it enforces it twice: bon has to agree with its noun in gender and number, and bien has to stay exactly as it is.

So the choice is not a matter of register or politeness, it is grammar. J’aime le bon vin is about wine, a thing, and bon describes it. Je parle bien français is about the way I speak, and bien describes the verb. Swap them and the sentence is not casual, it is wrong, which is why this is one of the first things worth getting right.

Before you write either word, find what it is talking about. In c’est un bon professeur, good is attached to professeur, a person: it is the adjective, so it is bon, and it would become bonne for une bonne professeure. In il explique bien, good is attached to explique, the act of explaining: it is the adverb, so it is bien, and nothing can change it.

The test works because it matches what the two words are. An adjective belongs to a noun, an adverb belongs to a verb, and French keeps those two jobs separate in a way English has stopped doing. It also explains the rest of the page: every apparent exception below is a case where the word is attached to something other than what you first assumed.

One shortcut that holds most of the time: if the word comes right after être and refers back to the subject, you are describing a noun, so you want bon. Ce fromage est bon, elle est bonne en maths. The exceptions to that shortcut, c’est bien and on est bien ici, have their own section further down.

Most French adjectives follow their noun: un vin rouge, une idée intéressante. Bon belongs to the small group of short, very common adjectives that go in front: un bon vin, une bonne idée, un bon moment. Watch the article in the plural, because des becomes de in front of an adjective placed before the noun: des résultats, but de bons résultats.

Bien, being an adverb, sits next to its verb instead. In a simple tense it follows the verb: il travaille bien, tu parles bien. In the passé composé and the other compound tenses it slips between the auxiliary and the participle: il a bien travaillé, nous avons bien mangé. Putting it after the participle, il a travaillé bien, is one of the clearest signs of an English speaker.

Both exist, and this is where the rule earns its keep. C’est bon judges a thing, most often something you can taste: ta soupe, c’est bon. The noun is hiding in plain sight, the soup, so French uses the adjective. C’est bon also means that is enough or it works, which is what you hear all day: c’est bon, j’ai fini; ça y est, c’est bon.

C’est bien judges an action, an idea, a decision, something with no object you can point at: faire du sport, c’est bien; tu as appelé ta mère, c’est bien. Nothing tangible is being described, so French uses the adverb. The same split gives il est bon, he is good at what he does or it tastes good, against il est bien, he is a decent person or he looks good.

Être bien also means to be comfortable, which has no equivalent with bon: on est bien ici, we are comfortable here; je suis bien dans ce fauteuil. And for health it is always the adverb: je vais bien, tu vas bien ? Je vais bon does not exist.

Two extra jobs make bien look unpredictable, and both are worth recognising. The first is intensity: in front of another adjective or adverb, bien means very or much. Je suis bien content, c’est bien plus simple, elle va bien mieux. With a noun it becomes bien des, meaning many: bien des gens, bien des choses.

The second is informal but everywhere: bien used as an adjective, meaning decent, worthwhile, good-looking. C’est un film bien, c’est quelqu’un de bien, elle est bien. Even there it never agrees, so the spelling question never arises. Note the difference in meaning that stays behind it: elle est bonne is about ability or taste and can sound crude about a person, elle est bien is about character or looks.

One last pair that follows the same logic: très bon and très bien. Très bon goes with a noun, c’est un très bon restaurant; très bien goes with a verb, elle chante très bien. And on its own, très bien is the all-purpose way of saying fine, agreed.

Neither word takes plus. Bon has its own comparative, meilleur, which agrees like any adjective: ce vin est meilleur, une meilleure idée. Bien has mieux, which never changes: elle chante mieux que moi. Plus bon and plus bien do not exist, exactly as English has better rather than more good.

Everything else behaves normally, though. Going down or staying level, both words take the usual words: ce café est moins bon que l’autre, elle chante aussi bien que lui. And for the superlative you add the article: le meilleur fromage, la meilleure solution, but always le mieux with a verb, c’est elle qui cuisine le mieux. The mieux vs meilleur poster below takes that half of the story further.