A compound sentence is a sentence that consists of two or more independent clauses, which are separate whole sentences on their own, that are connected together by a conjunction such as "and, or, and but" or a semicolon.
It is a sentence which contains two or more distinct clauses separated by conjunctions. A clause must generally contain a noun (or pronoun) and a verb. "The dog barked but nobody heard him" is a compound sentence, because it contains the clauses "The dog barked" and "nobody heard him" connected by the conjunction "but".
A compound sentence is one sentence made up of two independent clauses, joined by "and," "or," or "but. " For example, "I saw Billy run, BUT he didn't see me. "
