An adverb is a part of speech that modifies verbs, adjectives, or other adverbs. It provides additional information about how an action is performed, or the degree and intensity of an adjective or another adverb. For example, in the sentence “She runs quickly,” the adverb “quickly” describes how she runs.
The word "adverb" comes from the Latin term "adverbium," where "ad-" means "to" or "toward," and "verbum" means "word." Thus, it translates to "to the verb," indicating its function of modifying verbs.