Noun Clauses
Level B2–C2 · that-clauses, wh-clauses; embedding ideas
◎What you'll master
- See that a noun clause does a noun's job — subject, object, or complement.
- Build that-clauses (I believe that… · The fact that… · It is clear that…) and drop that when it's natural.
- Use wh-clauses and if/whether-clauses as objects (I don't know what she wants / whether it's true).
- Apply the key rule: an embedded question keeps statement order — no inversion, no do/does/did.
- Put a noun clause after be to explain or report an idea (The problem is that we're late).
1What a noun clause is
A noun clause is a whole clause (subject + verb) that behaves like a single noun. Wherever a noun could go — as the subject, the object of a verb, or the complement after be — a noun clause can go there too.
| Job | With a noun | With a noun clause |
|---|---|---|
| Subject | The truth surprised me. | That she lied surprised me. |
| Object | I know the answer. | I know what the answer is. |
| Complement | The problem is money. | The problem is that we're late. |
Most noun clauses begin with that, a wh- word (what, where, who, why, how…), or if / whether.
2That-clauses
A that-clause reports an idea, a fact, or a belief. It follows many verbs of thinking and saying.
Dropping "that"
After common verbs (think, believe, know, say, hope, feel…), that is optional in speech and informal writing. The clause is exactly the same with or without it.
The fact that… · It is clear that…
A that-clause can also sit after the fact, or be introduced by empty it so the heavy clause moves to the end.
3Wh-clauses as objects
A wh-clause turns a question word into a noun clause: what, where, when, who(m), whose, why, how, which. It often follows verbs like know, wonder, remember, decide, explain, tell, ask.
The whole wh-clause is the object of the main verb — so you can replace it with it or something and the sentence still stands: I don't know it.
4If / whether-clauses (yes-no ideas)
When the embedded idea is a yes/no question, use if or whether to introduce the noun clause.
5The key rule: embedded questions keep statement order
This is the point TOEFL tests most. A direct question inverts the subject and auxiliary (Where does she live?). But once that question is embedded inside a bigger sentence, it goes back to plain statement order: no inversion, and no do / does / did.
| Direct question | Embedded noun clause |
|---|---|
| Where does she live? | Tell me where she lives. |
| What time is it? | Do you know what time it is? |
| Why did they leave? | I don't understand why they left. |
| When will they arrive? | Ask them when they will arrive. |
| Did he call? | I wonder if he called. |
6Noun clauses after 'be' — reporting & embedding smoothly
A noun clause after be works as a complement — it renames or explains the subject. This is a clean way to state a problem, a point, or a question.
Using noun clauses lets you fold a whole idea into a sentence and report it smoothly instead of quoting a raw question or statement.
I think ______ right.
I don't know ______ .
I wonder ______ true.
He knows ______ waiting.
Do you know what time ______ ?
She asked me ______ .
______ he apologised means a lot to me.
It is clear ______ , even though nobody has said so directly.
The question we kept coming back to was ______ the plan was worth the risk at all.
✎Fix the Error
Each sentence has one mistake in the underlined word. Type the correction and check.
1.I don't know where does she live .
2.Tell me what time is it .
3.I wonder did he call last night.
4.Do you know when will they arrive ?
5.She asked me where do I work .