It cannot stand alone as a sentence. A phrase is a group of words used as a sentence part. It does not have a subject and a verb. It can be a noun, adjective or adverb. A compound sentence combines two or more independent clauses .
Commas separate the clauses of a compound sentence.
A semicolon can take the place of the conjunction and comma. Only clauses closely related in thought should be joined to make a compound sentence. Tell if the following sentences are good combinations. Mr. Jones is a very short man, but he walks with an air of authority. Today has been very warm, and I have some English lessons to write.