A complex sentence is a sentence made up of an independent clause (one that expresses a complete thought) and a dependent clause (one that can not stand alone as a sentence because it does not express a complete idea). In this type of sentence, the dependent clause is often introduced by a coordinating conjunction such as<em> </em><u><em>while</em></u> (like in the sentence),<em> after, because, since, if, although </em>and<em> until.</em>
<em>While the others went swimming, we made a sand castle</em> is an example of this type of sentence because it has a dependent clause: <u><em>While the others went swimming</em></u> and an independent clause <u><em>we made a sand castle.</em></u>
