English Grammar Understanding the Basics

In the last lesson, we talked about compound sentences such as:

1. Beth said hello to her mother's friend and then she walked outside.

Each of the sentences (clauses) that is part of the compound sentence plays an equal role in the sentence; one clause is not superior to or more important than the other, in terms of the structure of the sentence.

Now let's look at some other sentences:

1. 2. Harry was only fifteen when his mother sent him away to school.

2. 3. Mr. Edwards looked her straight in the eye although he wasn't really sincere.

3. 4. I won't tell you the answer unless you agree to help.

Sentences 2–4 also each contain two sentences, or clauses, which are combined to make a larger sentence. However, one of these sentences is more important than the other. The more important sentence is called the main clause, or independent clause; the less important sentence, the one that is a subpart of the main clause, is called the dependent clause or subordinate clause (see Lesson 19). Each clause, whether it's a main clause or subordinate clause, has its own subject and verb phrase. Sentences that contain a main clause and at least one dependent clause are called complex sentences.