complex sentence

A complex sentence comprises one independent clause and at least one dependent clause. The dependent clause, which cannot stand by itself as a sentence, performs some grammatical function in the complex sentence. In the following example* of a complex sentence, notice the grammatical functions of the three underlined dependent clauses:

Although it wasn't true, Mike told everyone that he had lent his bike to the boy who lived next door.

Here are the grammatical functions of the main clause and the three dependent clauses:

Although it wasn't true, (adverbial clause modifying entire sentence)

Mike told everyone (the main clause)

that he had lent his bike (noun clause, direct object of told)

to the boy who lived next door. (adjectival clause modifying boy)

* Thomas S. Kane, The Oxford Guide to Writing p. 218 (1983).