1. A phrase is a group of related words that does not contain both a subject and a verb, while a clause contains both a subject and a verb.
2. A phrase cannot stand alone as a sentence, but a clause may be able to stand alone as a sentence if it is an independent clause.
3. There are two main types of clauses: independent clauses, which can stand alone as complete sentences, and subordinate clauses, which cannot stand alone and must be attached to an independent clause.