Adverbs of manner specify how an action is done. In a sentence like She speaks softly, the adverb adds information about the manner of speaking. Without it, we only know that the action exists: She speaks. With it, we know the tone, attitude, or way of acting. They often answer the question how? and can also nuances a verb, an adjective, or sometimes another adverb. To review the general notion of adverbs, consult Adverbes.

Many adverbs of manner are formed from an adjective. The most common form uses the feminine form of the adjective + -ment: heureuse + -ment gives heureusement, douce + -ment gives doucement. When the masculine adjective ends with a vowel, one often simply adds -ment to the masculine form: vrai + -ment gives vraiment. This formation is used to create adverbs such as sérieusement, lentement or clairement. The derivation logic is detailed in Formation des adverbes.

Some adjectives ending in -ant give adverbs in -amment, and some adjectives ending in -ent give adverbs in -emment. For example, brillant + -amment = brillamment and récent + -emment = récemment. These forms keep the sense of manner, but their spelling changes according to the origin adjective. In this group, you must recognize the starting ending to produce the correct form. These adverbs belong to the same system as the other manners adverbs, and they are useful for uses related to Adverbes de fréquence and Adverbes de temps when they accompany an action.

Some adverbs of manner are not built with a visible rule. Bien and mal are the most well-known forms. Bien expresses a correct or satisfactory manner: Il travaille bien. Mal indicates an incorrect or insufficient manner: Tu écris mal. Other very common forms like vite or ensemble are used directly, without going through a recognizable adjective. They must be learned as complete words, because their form does not reveal their origin. Several of these adverbs also serve to nuance the strength of a statement, as in uses studied with Adverbes de quantité.

Adverbs of manner do not change for gender or number. The form remains the same in all sentences: Il chante fort, Elle chante fort, Ils chantent fort. The adverb never agrees with the subject, nor with a noun, nor with an adjective. It is the context that shows its function, not a mark of agreement. When the adverb modifies an adjective, it always keeps its fixed form, as in très calme or extrêmement utile. This property is the same as for the other groups described in Adverbes de lieu.

The most common placement of adverbs of manner is after the verb: She responds politely, They walk quickly. With a compound verb, the adverb often goes after the past participle: She has worked carefully. Short adverbs like bien, mal, vite can also come before the past participle or at the beginning of the sentence to emphasize the manner: Bien entendu, he refused or Vite, they closed the door. When the adverb accompanies another element, it goes just before what it modifies: très rapidement, assez calmement. This arrangement aligns with usages observed in other types of adverbs, notably Adverbes de temps.