The adverb specifies the meaning of a verb, of an adjective, of another adverb, or of an entire sentence. It often expresses manner, time, quantity, degree or viewpoint. In French, it is generally invariable, so its form does not change according to gender or number.

The most common formation consists of taking the feminine form of the adjective and adding -ment. This method yields adverbs such as lentement from lent and rapidement from rapide. When the adjective ends with an e, one simply adds -ment to the existing base.

RègleRule	ExempleExample
On forme souvent l’adverbe avec la forme féminine suivie de ment.Adverbs are often formed with the feminine form followed by -ment.	Lent devient lentement.Lent becomes lentement.
Quand l’adjectif finit par e, on ajoute ment sans changer la base.When the adjective ends with e, you simply add -ment to the base without changing it.	Rapide devient rapidement.Rapide becomes rapidement.
L’adverbe ne varie pas selon le nom ou le sujet.The adverb does not vary with the noun or the subject.	Elle parle rapidement.She speaks quickly.

Certain endings impose a precise orthographic transformation. Adjectives ending in -ant take -amment, as when bruyant becomes bruyamment, while adjectives ending in -ent take -emment, as when récent becomes récemment. Accents and double consonants must be preserved when orthography requires them, as in vraiment and récemment.

RègleRule	ExempleExample
Un adjectif en ant devient souvent un adverbe en amment.An adjective ending in -ant often becomes an adverb ending in -amment.	Bruyant devient bruyamment.Bruyant becomes bruyamment.
Un adjectif en ent devient souvent un adverbe en emment.An adjective ending in -ent often becomes an adverb ending in -emment.	Récent devient récemment.Récent becomes récemment.
Certaines formes gardent un accent ou une consonne double.Some forms preserve an accent or a double consonant.	Vraiment et récemment gardent leur orthographe.Vraiment and récemment keep their spelling.

Some very common adverbs do not follow the ordinary formation rule and must be memorized. Bien, mal, vite and loin belong to this group. Their usage is very common and they appear in contexts of manner, degree or distance.

RègleRule	ExempleExample
Bien est une forme irrégulière fréquente.Bien is a common irregular form.	Elle chante bien.She sings well.
Mal est une forme irrégulière fréquente.Mal is a common irregular form.	Il comprend mal.He understands it badly.
Vite est une forme irrégulière fréquente.Vite is a common irregular form.	Ils avancent vite.They move quickly.
Loin est une forme irrégulière fréquente.Loin is a common irregular form.	Elle habite loin.She lives far away.

Some time adverbs or fixed expressions function as adverbs without being built by a productive rule. Aujourd’hui, demain and souvent belong to this group and serve to situate the action in time or frequency. In colloquial language, speech may shorten certain forms, and in literature, a long form may sometimes be replaced by a shorter form depending on the desired effect.

RègleRule	ExempleExample
Des expressions figées peuvent jouer le rôle d’adverbes.Fixed expressions can play the role of adverbs.	Aujourd’hui marque le présent.Aujourd’hui marks the present.
Certains adverbes de temps sont très fréquents.Some time adverbs are very common.	Demain annonce l’avenir.Demain points to the future.
Le choix de forme peut dépendre du style.The choice of form may depend on style.	Soudain peut remplacer soudainement.Soudain can replace soudainément.

An adverb is invariable and its place depends on the element it modifies. It often follows the verb it modifies, before an adjective or before another adverb, as in très grand. For the order of complements and adverbs in the sentence, the link with Place of Adverbs is essential.

RègleRule	ExempleExample
L’adverbe suit souvent le verbe qu’il précise.The adverb often follows the verb it modifies.	Elle parle doucement.She speaks slowly.
L’adverbe précède souvent un adjectif.The adverb often precedes an adjective.	Un jardin très grand.A very large garden.
L’adverbe précède souvent un autre adverbe.The adverb often precedes another adverb.	Il répond très vite.He answers very quickly.

Forming an adverb basically comes down to recognizing the base of the adjective and choosing the expected ending. The general rule goes through the feminine form + ment, while -ant becomes -amment and -ent becomes -emment. The irregular forms, fixed expressions and the position in the sentence complete the essential formation of adverbs in French.