“Dependent Clause: A group of words that includes a subject and verb but is subordinate to and independent clause in a sentence. Dependent clauses begin with either a subordinating conjunction, such as if, because, since, or a relative pronoun, such as who, which, that. When it gets dark, we’ll find a restaurant that has music.”
Excerpted from: Strunk, William Jr., and E.B. White. The Elements of Style, Fourth Edition. New York: Longman, 2000.