An ADJ. MODIFER is an adjective that modifies a noun or pronoun in a sentence. It is used to describe the quality, state, or action of the noun or pronoun. An example of an ADJ. MODIFER is 'HAPPY, ' which modifies the noun 'DOG' in the sentence 'The HAPPY DOG RAN around the yard.' An ADV. (3 letters) is an adverb, which is a word that modifies or describes a verb, an adjective, or another adverb. An example of an ADV. (3 letters) is 'QUICKLY, ' which modifies the verb 'RAN' in the sentence 'The HAPPY DOG QUICKLY RAN around the yard.'