English has three common types of dependent clauses: noun clauses, relative clauses and adverb clauses. It would be unusual to write a paragraph or talk for a few minutes without using at least one of these. In fact, in my first few paragraphs alone, I have used at least two of these types of clauses.

Ultimately, understanding how clauses work will help you identify and avoid incomplete or structurally unsound sentences. And this will strengthen your speaking skills – and especially your writing skills.

What is a clause?

As I just said, a clause is a group of words with a subject and a verb. But that structure alone does not guarantee a complete sentence. Clauses can be dependent, or incomplete, or independent or complete.

Every complete sentence in English contains at least one clause; many sentences have two or more clauses.

So, let’s return to our example about dance. If I said to you, “I never miss Samantha’s class because I love to dance,” I would be expressing myself in a complete sentence.

The sentence has two clauses: “I never miss Samantha’s class” and “because I love to dance.”

Independent clauses

Independent clauses contain the main subject and main verb of a sentence. They express clear thoughts and can stand alone as sentences. In our example, “I never miss Samantha’s class” is an independent clause. It is a complete sentence on its own and does not need “because I love to dance” to express a complete thought.

In sentences containing more than one clause, independent clauses are usually called “main clauses.”

Dependent clauses

Now, let’s talk about dependent clauses, also called “subordinate clauses.” Remember, the clause “because I love to dance” contains a subject and verb, but it is still dependent. It leaves you feeling like something is missing. Another good indication that this clause is dependent is that the word “because” signals an adverb clause. But, it only contains one subject and one verb. So, the other part of the sentence – the independent clause -- is missing.

Dependent clauses depend on – or need – independent clauses to express complete thoughts.

Listen to more examples of dependent clauses and decide for yourself: does it seem like something is missing? Listen:

If my aunt arrives by 3pm. That’s an adverb clause.

Who lives in the building. That’s a relative clause.

What you did last summer. That’s a noun clause.

Again: All of these are dependent clauses: They leave you knowing that you need more information to get the complete idea. Words like if, because, who, what, that and other words often – but not always -- signal dependent clauses.

Now, let’s listen to complete sentences for each example:

We can still see the monuments today if my aunt arrives by 3pm.

My friend who lives in the building is away this weekend.

I know what you did last summer.

You may recognize this third sentence as the title of a 1997 American horror film, adapted from a book of the same title.

Each of the examples contains two clauses: a dependent clause connected to an independent clause.

Remember – independent clauses express complete thoughts by themselves. So, “We can still see the monuments today”; “My friend is away this weekend”; and even “I know” are all independent clauses – they are complete sentences on their own. However, their dependent clauses provide more information.

Is it a sentence?

Ok, so we learned that some clauses are complete sentences and some are not. Now, let’s practice a bit.

Listen to some examples. Are they complete sentences? Can you locate the dependent clauses? The independent clauses?

Listen:

After we visited the French Market on Saturday.
Who is crossing Broad Street.
She works with a computer that is older than she is.
I wish that I could live by the beach all summer.
The box that is near the elevator.