Adverbs in French, like in English, 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.
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 -nt is stripped and -mment is added:
