An adjective describes or modifies a noun or pronoun by telling which one, what kind, or how many. An adverb describes or modifies verbs, adjectives, and other adverbs by telling when, where, or how something occurred. Adjectives provide details about nouns, such as the color of a sweater. Adverbs provide details about verbs and other parts of speech, such as how quickly or slowly something was done. Both adjectives and adverbs add description to language.