What is a noun clause? What are its functions, how is it structured, and how can it be reduced? Let IDP help you explore everything about noun clauses to strengthen your English grammar and boost your IELTS performance.
Many IELTS candidates feel confused when encountering noun clauses. In essence, a noun clause functions like a noun in a sentence, helping you form more complex sentence structures while maintaining high grammatical accuracy. In this guide, IDP explains the theory, structure, and reduction of noun clauses, along with practice exercises and answer keys.
1. What Is a Noun Clause?
A noun clause (also known as a nominal clause) is a dependent clause that functions like a noun. It can act as a subject, object, or complement in a sentence.
Example:
What I told everyone at the party surprised them.
Here, the clause What I told everyone at the party functions as the subject of the sentence and plays the role of a noun.
2. Structure of Noun Clauses
Noun clauses usually appear in complex sentences and follow this basic structure:
WH- / That / Whether / If + S + V
Noun clauses typically begin with:
WH- question words: what, why, who, where, when, how, etc.
Conjunctions: whether, if
That: used to introduce statements
Examples:
Why Sarah quit her job is still unknown.
That the boy can play the piano at his young age is very impressive.
Being honest and loyal is how you build a true relationship.
3. Functions and Positions of Noun Clauses in Sentences
As the Subject of the Sentence
Structure: What / Where / Why / When / That / If / Whether + S + V1 + V2
Examples:
How you made that decision baffles me.
What they do for you is precious.
Where he lives is a mystery to me.
As the Object of the Sentence
Noun clauses can function as:
Object after verbs: Structure: S + V1 + WH- / That / If / Whether + S + V2
Examples:
The mediator will give what you said full consideration.
Sarah said that she would find a better job in the city.
I am not sure which backpack is mine.
Object after prepositions: Structure: S + V1 + prep + WH- / That / If / Whether + S + V2
Examples:
Her team is confident in what they can achieve.
You do not need to worry about what they have done.
As a Subject Complement
Structure: S + to be + WH- / That / If / Whether + S + V
Examples:
The truth was that the home team came back from a 20-point halftime deficit.
My question is whether he will attend the meeting.
The story is that he tried to propose but she said no.
As an Adjective Complement
Structure: S + to be + That / Whether / If + S + V
Examples:
It is very disappointing that you left the party early.
She was surprised that he remembered her birthday.
The teacher is proud that her students are making progress.
4. Reducing Noun Clauses
Noun clauses can be reduced in some cases to simplify your sentences. You can reduce a noun clause when:
It functions as an object
It has the same subject as the main clause
Reduction with To-Infinitive
Structure: S + V1 + WH- / That / If / Whether + to V
Examples:
This article tells how you can perform a task efficiently. → This article tells how to perform a task efficiently.
You do not need to worry about what they have done. → You do not need to worry about what to do.
Reduction with V-ing
Structure: S + V1 + V-ing
Examples:
I hate that I do homework every day. → I hate doing homework every day.
I appreciated that I had the chance to do things I like. → I appreciated having the chance to do things I like.
5. Notes on Using Noun Clauses
Do Not Confuse Noun Clauses with Questions
Since noun clauses often begin with what, why, when, etc., they can be mistaken for questions. Remember that in noun clauses, the verb follows the subject — do not invert the order as you would in questions.
Example:
I can’t remember how old was she. ❌ → I can’t remember how old she was. ✅
Include a Verb in Every Noun Clause
Noun clauses must contain a verb to be grammatically complete.
Example:
Why Sarah quit her job still unknown. ❌ → Why Sarah quit her job is still unknown. ✅
Use the Correct Verb Form
Be careful when conjugating the main verb after a noun clause.
Example:
We think that Mr. Smith are here at 10 am tomorrow. ❌ → We think that Mr. Smith will be here at 10 am tomorrow. ✅
6. Noun Clause Exercises with Answers
Exercise 1: Rewrite the following as noun clauses
I don't know. What kind of battery is this? → I don't know what kind of battery it is.
My brother doesn't know for sure. How tall is he? → My brother doesn't know for sure how tall he is.
I didn’t remember. Which chapter were we on? → I didn’t remember which chapter we were on.
The ads said. Their products can cure cancer. → The ads said that their products can cure cancer.
Where is Sarah? No one knew about it. → No one knew where Sarah is.
Could you show me? Where is the bookshop? → Could you show me where the bookshop is?
Do you have a plan? How long will we stay in Seoul? → Do you have a plan on how long we will stay in Seoul?
Please tell us. What did you hear last night? → Please tell us what you heard last night.
Exercise 2: Combine the sentences using noun clauses
I do not understand. What kind of water is this? → I do not understand what kind of water this is.
My mother wants to know. How old is she? → My mother wants to know how old she is.
I am insecure. Which pages are we reading? → I am insecure about what pages we are reading.
Presidents claim. They will progress covid-19 vaccine. → Presidents claimed that they will progress the covid-19 vaccine.
Who is that boy? Everyone knows. → Everyone knows who that boy is.
Could you show me? Where is the post office? → Could you show me where the post office is?
Do you remember? How long have we learned French? → Do you remember how long we have learned French?
Please tell us. What did you see? → Please tell us what you saw.
Master Noun Clauses with IDP IELTS
Now that you have a complete understanding of Noun Clauses, including functions, structures, and how to reduce them, remember to practice daily to master this grammar point. IDP provides personalized practice materials designed to match your current skill level.
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