French adverbs, like their English counterparts, are used to modify adjectives, other adverbs, and verbs or clauses. They do not display any inflection; that is, their form does not change to reflect their precise role, nor any characteristics of what they modify. An adverb is a part of speech that usually serves to modify verbs, adjectives, other adverbs, clauses, and sentences. ... The English language is a West Germanic language that originates in England. ... An adjective is a part of speech which modifies a noun, usually making its meaning more specific. ... A verb is a part of speech that usually denotes action (bring, read), occurrence (to decompose (itself), to glitter), or a state of being (exist, live, soak, stand). Depending on the language, a verb may vary in form according to many factors, possibly including its tense, aspect, mood and voice. ... A clause is a group of words consisting of a subject (often just a single noun) and a predicate (sometimes just a single verb). ... Inflection or inflexion refers to a modification or marking of a word (or more precisely lexeme) so that it reflects grammatical (i. ...

Formation

In French, as in English, most adverbs are derived from adjectives. In most cases, this is done by adding the suffix -ment ("-ly") to the adjective's feminine singular form. For example, the feminine singular form of lent ("slow") is lente, so the corresponding adverb is lentement ("slowly"); similarly, heureux → heureusement ("happy" → "happily").

As in English, however, the adjective stem is sometimes modified to accommodate the suffix:

• If the adjective ends in an i, then -ment is added to the masculine singular (default) form, rather than to the feminine singular form:
  • vrai → vraiment ("real" → "really")
  • poli → poliment ("polite" → "politely")
• If the adjective ends in -ant or -ent, then the corresponding adverb ends in -amment or -emment, respectively:
  • constant → constamment ("constant" → "constantly")
  • récent → récemment ("recent" → "recently")
• Some adjectives make other changes:
  • précis → précisément ("precise" → "precisely")
  • gentil → gentiment ("nice" → "nicely")

Some adverbs are derived from adjectives in completely irregular fashions, not even using the suffix -ment:

• bon → bien ("good" → "well")
• mauvais → mal ("bad" → "badly")
• meilleur → mieux ("better"-adjective → "better"-adverb)
• pire → pis ("worse"-adjective → "worse"-adverb)

And, as in English, many common adverbs are not derived from adjectives at all:

• ainsi ("thus" or "thusly")
• vite ("quickly")

Placement

The placement of French adverbs is almost the same as the placement of English adverbs.

An adverb that modifies an adjective or adverb comes before that adjective or adverb:

• complètement vrai ("completely true")
• pas possible ("not possible")
• trop bien cuit ("too well cooked" or "overdone")

An adverb that modifies an infinitive (verbal noun) generally comes after the infinitive: In grammar, the infinitive is the form of a verb that has no inflection to indicate person, number, mood or tense. ... A noun, or noun substantive, is a part of speech (a word or phrase) that refers to a person, place, thing, event, substance or quality. ...

• marcher lentement ("to walk slowly")

But negative adverbs, such as pas ("not"), plus ("not any more"), and jamais come before the infinitive:

• ne pas marcher ("not to walk")

An adverb that modifies a main verb or clause comes either after the verb, or before the clause:

• Lentement il commença à marcher or Il commença lentement à marcher ("Slowly, he began to walk" or "He began slowly to walk").

Note that, unlike in English, this is true even of negative adverbs:

• Jamais je n'ai fait cela or Je n'ai jamais fait cela ("Never have I done that" or "I've never done that")