Most French adverbs of manner (slowly, happily, politely...) are built directly from an adjective, similar to English "-ly."
1. Regular formation: feminine adjective + -ment
| lent → lente → lentement | slow → slowly |
| heureux → heureuse → heureusement | happy → happily, fortunately |
| doux → douce → doucement | soft → gently, softly |
2. Adjectives already ending in a vowel: skip the feminine
If the masculine form already ends in a vowel, add -ment directly to it, there's no need to switch to the feminine first.
| vrai → vraiment | true → truly (not "vraiement") |
| poli → poliment | polite → politely |
| absolu → absolument | absolute → absolutely |
3. Watch out: -ant/-ent become -amment/-emment
Common mistake: adjectives ending in -ant or -ent don't just add -ment, the ending changes to -amment or -emment, and both are pronounced the same way: /amɑ̃/. constant → constamment (constantly), patient → patiemment (patiently).
4. Irregular adverbs
| bon → bien | good → well |
| mauvais → mal | bad → badly |
5. Position: after the verb
In simple tenses, the adverb goes right after the conjugated verb. In the passé composé, short common adverbs (bien, mal, déjà, souvent, toujours...) slide in between avoir/être and the past participle, longer adverbs usually stay after the participle.
| Il parle lentement. | He speaks slowly. |
| Il a bien mangé. | He ate well. (bien between avoir and the participle) |
| Il a parlé lentement. | He spoke slowly. (longer adverb, after the participle) |