What is a Noun Clause?
A noun clause is a dependent clause that acts as a noun. Just like a single-word noun, a noun clause can be a subject, an object, or a complement.
The easiest way to identify a noun clause is to see if you can replace the entire clause with the pronoun "it" or "something."
- I know that he is a good person.
I know something.
Why she left is a mystery.
- It is a mystery.
Types of Noun Clauses
Noun clauses are identified by the word they begin with.
1. "That" Clauses
These clauses state facts, opinions, or beliefs. The word "that" is often omitted, especially in informal speech.
- I believe that everything happens for a reason.
- I believe everything happens for a reason. ("that" is omitted)
- That she didn't call is strange. (As a subject, "that" cannot be omitted)
2. "Wh-" Word Clauses
These clauses begin with words like what, who, when, where, why, which, how. They are also known as interrogative clauses because they are based on questions.
IMPORTANT: The word order in a "Wh-" noun clause is a statement, not a question.
| Question | Noun Clause |
|---|---|
| Where is he? | I don't know where he is. |
| What did she say? | Please tell me what she said. |
| Why are they laughing? | Why they are laughing is not important. |
3. "If / Whether" Clauses
These clauses report a yes/no question.
- If is more common and informal.
- Whether is more formal and can be used with "or not."
- I wonder if he will come to the party.
- She asked whether the flight was delayed.
- He couldn't decide whether or not to accept the job.
Functions of Noun Clauses in a Sentence
As a Subject:
The clause is the one performing the action.
- What he said made me angry.
- That the project was successful was a relief.
As an Object of a Verb:
The clause receives the action of the verb. This is the most common function.
- She knows how to bake a cake.
- I don't remember where I parked my car.
- I think (that) you are right.
As an Object of a Preposition:
The clause follows a preposition like for, about, of, to.
- Pay attention to what the teacher says.
- We were talking about where we should go on vacation.
As a Subject Complement:
The clause follows a linking verb (like is, was, seems) and renames or describes the subject.
- The problem is that we don't have enough time.
- My question is if this is the right decision.
Common Errors and How to Fix Them
| ✗ Incorrect | ✓ Correct | Why |
|---|---|---|
| I don't know where is he. | I don't know where he is. | Noun clauses use statement word order, not question order. |
| She asked me that what I was doing. | She asked me what I was doing. | Do not use "that" with a "wh-" word. |
| That you are happy, is important. | That you are happy is important. | Do not put a comma after a noun clause that is the subject. |
Summary
| Clause Starter | Type | Example |
|---|---|---|
| that | Statement of fact/opinion | I know that you're busy. |
| wh- words | Based on an information question | Tell me what happened. |
| if / whether | Based on a yes/no question | I'm not sure if I can go. |
💡 The key takeaway: A noun clause is a group of words with a subject and verb that acts as a single noun. Watch out for word order in clauses beginning with question words!