DEFINITION
A clause is a group of words containing a subject and a predicate.
independent clause
An independent clause (or main clause) contains a subject and predicate, and it can express a complete thought. It can stand on its own.
subordinate clause
A subordinate clause (or dependent clause) contains a subject and predicate, but it cannot express a complete thought. You need to pair it with an independent clause to form a sentence; otherwise, it’s a fragment. A subordinate clause can function as an adjective, noun, or adverb.