This document discusses dependent and independent clauses. It defines a dependent clause as a group of words with a subject and verb but not expressing a complete thought on its own. Dependent clauses often begin with words like "when", "because", or "until". An independent clause can stand alone as it expresses a complete thought with a subject and verb. The document provides examples of dependent and independent clauses and discusses how they can be used to form simple, compound, and complex sentences.