An adjective is a word that describes or modifies a noun or a noun substitute. Note that adjectives cannot be used to modify verbs, adverbs, or other adjectives. Therefore, you must be able to identify the function of the word being modified.
Most adjectives tell which one, what kind, or how many about the words they modify or describe.
Four green leaves fell off my favorite plant. The cake in the oven smells delicious. He was friendly and cheerful. Mary considered the movie sad. An adverb is a word that describes or modifies a verb, an adverb, or an adjective.