5-1 Complex Sentences

In English, there are four different kinds of sentences. In previous units, you learned about simple and compound sentences. The third type is called the complex sentence.

Complex sentences contain one independent clause and one or more dependent clause.

A dependent clause is a group of words with a subject and verb that doesn't make complete sense on its own. It is an incomplete idea.
Dependent clauses need to go with an independent clause in order to be complete.

Dependent clauses begin with words like:

Look at the following sentences. These are examples of independent clauses, also called simple sentences:

These sentences are grammatically complete and have a complete idea. Now look at the following dependent clauses:

The above sentences don't make complete sense. They need to go with an independent clause to be understood. Now look at the the following examples of complex sentences. The independent clauses are in blue, and the dependent clauses are in green.

In a complex sentence, the clauses can come in either order. It is your choice. If we start a sentence with an independent clause and then a dependent clause, we do not need to use commas. However, if the dependent clause comes before the independent clause, we must put a comma after the dependent clause.

Again, the independent clauses are in blue, and the dependent clauses are in green. Commas are in orange.