Noun Clauses: The Clauses That Act as Subjects and Objects
Master noun clauses — how they work as subjects, objects, and complements — with clear rules, examples, and exam-focused practice.
A noun is a word: happiness, Delhi, teacher. A noun phrase is a group of words: the tall man from Delhi. A noun clause is an entire clause that functions as a noun.
What he said surprised everyone.
The clause what he said is the subject of the sentence. It answers the question what surprised everyone? — just like a noun would.
Noun clauses are among the most important structures in English grammar, and they appear constantly in both exams and formal writing. This article explains how to identify them, how they function, and how to avoid the most common errors.
Rule box: A noun clause is a dependent clause that functions as a noun — as a subject, object, complement, or appositive. It often begins with that, whether, if, what, why, how, when, where, who, whoever, whatever.
When a noun clause is the subject, it comes before the verb.
What he said is true.
Whether he comes doesn’t matter.
That she passed is wonderful news.
How he escaped remains a mystery.
Note: When a noun clause is the subject, the verb is usually singular.
❌ What he said are true.
✅ What he said is true.
A noun clause can be the object of a verb.
I know that he is honest.
She asked whether I was coming.
I don’t understand what you mean.
He explained how the machine works.
Do you know where she lives?
I am sure that he will come.
She was surprised by what he said.
We are thinking about whether we should go.
He insisted that he was right.
After linking verbs (be, seem, become), a noun clause can serve as a complement.
The problem is that we don’t have enough time.
The question is whether we can afford it.
That is what I meant.
The truth is that he never tried.
A noun clause can rename or explain another noun (usually fact, idea, news, hope, belief).
The fact that she passed made everyone happy.
I have no idea what he wants.
The news that the exam was cancelled relieved everyone.
His belief that hard work pays off kept him going.
| Introducer | Function | Example |
|---|---|---|
| that | Statement | I know that he is honest. |
| whether | Yes/no question | I wonder whether she will come. |
| if | Yes/no question (informal) | I wonder if she will come. |
| what | Thing(s) | I saw what happened. |
| why | Reason | I know why he left. |
| how | Manner | She explained how it works. |
| when | Time | I don’t know when he arrives. |
| where | Place | Do you know where she lives? |
| who | Person | I know who did it. |
| whoever | Any person | Whoever comes will be welcome. |
| whatever | Any thing | Whatever you decide is fine with me. |
- Can the clause answer “what?” → It is likely a noun clause.
- Is it the subject of the verb? → Noun clause as subject.
- Is it the object of a verb or preposition? → Noun clause as object.
- Does it follow a linking verb? → Noun clause as complement.
- Does it rename a noun? → Noun clause as appositive.
- Does it begin with that, whether, if, what, why, how, when, where, who? → Likely a noun clause.
- What he said is true. (subject)
- I know that he is honest. (object of verb)
- She asked whether I was coming. (object of verb)
- The problem is that we don’t have enough time. (complement)
- The fact that she passed made everyone happy. (appositive)
- I don’t understand what you mean. (object)
- Whether he comes doesn’t matter. (subject)
- I am sure that he will come. (object of preposition)
- Do you know where she lives? (object)
- Whoever finishes first will get a prize. (subject)
❌ I know where does he live.
✅ I know where he lives.
A noun clause uses statement word order (subject + verb), not question word order (auxiliary + subject + verb). Even if the clause begins with a question word, it is not a question.
❌ Can you tell me what is his name?
✅ Can you tell me what his name is?
❌ What he said are true.
✅ What he said is true.
A noun clause used as a subject takes a singular verb.
❌ Whether they agree don’t matter.
✅ Whether they agree doesn’t matter.
Both if and whether can introduce noun clauses, but whether is preferred in formal writing and after prepositions.
✅ I wonder whether she will come. (formal)
✅ I wonder if she will come. (informal)
✅ I am thinking about whether to go. (after preposition — formal)
❌ I am thinking about if to go. (after preposition — avoid)
Some verbs commonly take that-clauses: say, think, believe, know, hope, suggest, recommend, insist, agree, deny.
I suggest that he study harder. (subjunctive — base form)
I believe that she is honest. (indicative — normal verb form)
In formal English, verbs of suggestion (suggest, recommend, insist, demand, require) take the subjunctive — the base form of the verb without -s.
| Wrong | Right | Why |
|---|---|---|
| I know where does he live. | I know where he lives. | Statement word order in noun clause. |
| What he said are true. | What he said is true. | Noun clause subject = singular verb. |
| Whether he comes matter. | Whether he comes matters. | Singular verb needed. |
| I am sure that he will come. | ✅ Correct | Standard that-clause. |
Identify the noun clause and its function, or spot the error.
- ___ is unknown. (What he wants / What does he want)
- I don’t know ___ . (where she lives / where does she live)
- Error spotting: I know what is his problem.
- Error spotting: What they need are more resources.
- Error spotting: Whether he agrees don’t change anything.
- Fill in the blank: The fact ___ he passed made everyone happy. (that / what)
- Fill in the blank: I wonder ___ she will come. (if / whether)
- Identify the noun clause: She explained how the system works.
- Identify the function: That he is honest is well known.
- Rewrite correctly: I want to know what does he need.
- What he wants — subject noun clause.
- where she lives — object noun clause.
- I know what his problem is. — statement word order.
- What they need is more resources. — singular verb.
- Whether he agrees doesn’t change anything. — singular verb.
- that — appositive noun clause.
- whether — formal; if also acceptable informally.
- how the system works — object of explained.
- Subject — the noun clause is the subject of is.
- I want to know what he needs. — statement word order.
Rule: A noun clause functions as a noun — subject, object, complement, or appositive. It begins with that, whether, if, what, why, how, when, where, who. Use statement word order (not question order). A noun clause as subject takes a singular verb.
Memory trick: “Noun clauses answer ‘what?’ They use statement order. They take singular verbs. They begin with that, whether, what, why, how.”
Revise these:
- What he said is true. (subject)
- I know that he is honest. (object)
- The problem is that we don’t have time. (complement)
- The fact that she passed made everyone happy. (appositive)
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