Noun Clauses — That, What, Whether, and Wh-Words as Noun Clauses
Imagine you are in a team meeting in Bengaluru or preparing for your UPSC interview. You want to say more than just "I know the fact." You want to explain complex ideas like "I know that the project deadline has been moved" or "I don't understand why the client is unhappy." These longer groups of words are not random sentences—they are acting as a single noun. Mastering noun clauses lets you move beyond simple, choppy sentences and express professional, nuanced thoughts essential for higher-level English fluency.
A noun clause is a group of words with a subject and a verb that functions as a single noun. It can be the subject, object, or complement in a sentence.
1. What Is a Noun Clause?
A noun clause does the job of a noun. If you can replace a group of words with a pronoun like it or something, it is likely a noun clause.
Compare:
- I heard the news. (the news = simple noun phrase)
- I heard that Ravi won the prize. (that Ravi won the prize = noun clause acting as the object of heard)
Noun clauses are introduced by three types of words: That, Wh-words (who, what, where, when, why, how), and Whether/If.
| Sentence with a Noun | Sentence with a Noun Clause | Role of the Clause |
|---|---|---|
| I know the answer. | I know that the answer is C. | Object of know |
| His behaviour is odd. | How he behaves is odd. | Subject of the sentence |
| I am sure of his arrival. | I am sure that he will arrive. | Complement of an adjective (a clause that completes the meaning of an adjective) |
2. That-Clauses
The that-clause is the most common noun clause. It is used after reporting verbs like think, know, believe, say, feel, hope, realise, and find. In informal speech, we often drop that, but in formal writing—such as an email to your manager or an IELTS essay—it is better to keep it.
As an Object:
✅ Priya thinks that the Mumbai local will be late.
✅ The manager realised that the error was in the spreadsheet.
As a Subject:
✅ That he lied to the board is obvious to everyone.
✅ That she passed the CA exam on her first attempt is impressive.
After Adjectives:
✅ I am happy that you enjoyed the Diwali party.
✅ It is important that every student submits the assignment by Friday.
✍️ Quick Practice — The That Connector
Combine the two sentences using a that-clause.
- Neha is a great dancer. Everyone knows this.
- The weather will improve. We all hope for this.
- He failed the test. It is a pity.
Answers: 1. Everyone knows that Neha is a great dancer. | 2. We all hope that the weather will improve. | 3. It is a pity that he failed the test.
3. Wh-Word Noun Clauses
Noun clauses can begin with question words like what, who, where, when, why, and how. However, there is a golden rule: Always use statement word order, not question word order. This means the subject must come before the verb.
✅ I don't know where he is.
❌ I don't know where is he.
✅ Tell me what you want.
❌ Tell me what do you want.
✅ I wonder why she left early.
❌ I wonder why did she leave early.
✅ How they finished so fast is a mystery.
❌ How did they finish so fast is a mystery.
These clauses are powerful in formal writing. Instead of asking a direct question like "How can we reduce costs?", you can write: "We must investigate how we can reduce costs."
To check if a clause functions as a noun clause, try replacing it with something or it. To check if your word order is correct, ensure the subject comes before the verb (Subject + Verb) inside the clause, and do not use question helper verbs like do/does/did.
Example: ❌ I don't know where is he. → ✅ I don't know where he is.
4. Whether and If Noun Clauses
To turn a "Yes/No" question into a noun clause, use whether or if. However, when the noun clause functions as the subject of the sentence, you must use whether — if cannot be used in the subject position (e.g., "Whether he will come is uncertain" ✅, but "If he will come is uncertain" ❌).
- Direct Question: "Is Arjun coming to the wedding?"
- Noun Clause: "I am not sure if Arjun is coming to the wedding."
In formal writing and exams like the GMAT or GRE, whether is preferred over if. Whether is also used for two clear alternatives, often with "whether… or not."
✅ The committee will decide whether we should launch the product in Pune or Delhi.
✅ I don't care whether it rains or not; I am going for my morning walk.
✅ The question is whether we can afford the new software.
✍️ Quick Practice — Whether vs. Wh-Words
Fill in the blanks with the correct word (What/Where/Whether).
- I don't know _______ the office is open on Saturday.
- Please tell me _______ you said to the client.
- Do you know _______ the nearest ATM is?
Answers: 1. whether (or if) | 2. what | 3. where
5. Noun Clauses as Subjects (The It Dummy Subject)
In English, we rarely start sentences with a long that-clause because it feels "top-heavy." Instead, we use It as a dummy subject and move the noun clause to the end. This is a hallmark of professional writing.
| ✅ Natural/Professional (Using It) | ⚠️ Grammatical but Less Natural |
|---|---|
| It is clear that the economy is growing. | That the economy is growing is clear. |
| It is a mystery how he solved the puzzle without any help. | How he solved the puzzle without any help is a mystery. |
| It is unlikely that the flight will be on time. | That the flight will be on time is unlikely. |
Using "It + adjective + that-clause" is a great way to express opinions objectively in reports. For example: "It is recommended that the staff attend the training."
6. Common Mistakes by Indian Learners
Many learners carry the word order of their native languages into English, leading to errors in noun clause structure.
| ❌ Incorrect | ✅ Correct | Why? |
|---|---|---|
| I asked him what is his name. | I asked him what his name was. | Noun clauses use statement order (Subject + Verb). |
| She told me if I was hungry. | She asked me if I was hungry. | Told is for statements; asked is for if/whether clauses. |
| It depends on that he arrives. | It depends on whether he arrives. | Use whether for uncertainty/conditions after prepositions. |
| I don't know where does he live. | I don't know where he lives. | Do not use do/does/did in noun clauses. |
Summary
Learning to use noun clauses effectively will transform your writing from basic to sophisticated. Whether you are explaining a decision or reporting someone's words, these structures provide the framework you need.
- Noun clauses act as nouns (Subject, Object, or Complement).
- That-clauses are used for facts, beliefs, and reporting.
- Wh-clauses must always follow statement word order (Subject before Verb).
- Whether/If clauses are used for indirect Yes/No questions.
- Use the "It is…" structure to make your writing sound more natural when the noun clause is a subject.
Key takeaway: Next time you write an email, try to replace a simple noun with a noun clause. Instead of "I discussed the plan," try "I discussed how we can implement the plan." This small change shows a much higher level of English mastery.