* Sentence Complements are words or phrases that complete the meaning of a verb or a subject. They provide essential information about the subject or verb.
* Adverbs modify verbs, adjectives, or other adverbs. They provide information about how, when, where, or to what extent something happens.
Examples:
* Sentence Complement: "He is a doctor." (The noun phrase "a doctor" completes the meaning of the verb "is" and tells us what he is.)
* Adverb: "He walked quickly." (The adverb "quickly" modifies the verb "walked" and tells us how he walked.)
Therefore, an adverb cannot fulfill the role of a sentence complement because it does not complete the meaning of a verb or subject. It only modifies other words.