A complex sentence contains a main clause plus one or more subordinate, or dependent, clauses. Like a main clause, a subordinate clause contains a subject and a verb. But unlike a main clause, a subordinate clause doesn’t amount to a complete thought and so cannot stand on its own as a sentence. It is subordinate to, or dependent on, a main clause. Complex sentences are good for indicating which of two or more ideas is your focus.

The focus of this sentence is on how the writer’s parents feel about their careers. The subordinate clause (who are both lawyers) adds information that will give readers a fuller understanding of the main clause (My parents find their careers fulfilling).

The same information could be conveyed in a compound sentence, like this:

My parents are both lawyers, and they find their careers fulfilling.

But the emphasis is different. This version gives equal emphasis to the fact that the writer’s parents are both lawyers and the idea that they find their careers fulfilling.

To place one idea in the background of another, you may be able to subordinate the clause with one of these relative pronouns:

that,  which,  who,  whom,  whose

For more on who and whom.

Another kind of subordinate clause contains a main clause but begins with a subordinating conjunction.

The most common subordinating conjunctions are these:

A sentence that consists only of a subordinate clause feels incomplete and is an incorrect fragment:

Though I would love to make as much money as my parents do.

Usually, a fragment can be corrected by attaching it to the sentence before or after it:

I hope to be a music critic, though I would love to make as much money as my parents do.

Though I would love to make as much money as my parents do, I do not love the idea of becoming a lawyer.