NOUN CLAUSES EXERCISE 2 – WHAT OR THAT?
B1–B2 · IntermediateUseful for:✓ TOEFL
This second noun-clause exercise isolates the difference between what and that. Use what when it means “the thing that,” and that when it introduces a statement.Need a refresher? Review the grammar ↓
Choose the correct word to introduce each noun clause.
1. _______________ he said is not important.
Correct answer: What — what introduces a noun clause that is the subject — what he said = the thing he said.
2. _______________ she passed her exam didn't surprise us.
Correct answer: That — that introduces a noun clause as the subject — a factual statement, not a question.
3. How many people know _______________ I'm talking about?
Correct answer: what — what after a preposition refers to a thing — what I'm talking about.
4. She didn't think ________________ her mother would find out.
Correct answer: that — that after think introduces a factual noun clause.
5. _______________ my brother does on his own time is not your business.
Correct answer: What — what introduces a noun clause as subject — refers to the specific thing he does.
6. I noticed _______________ she was upset.
Correct answer: that — that after noticed introduces a factual noun clause.
7. It's too bad ________________ you can't go.
Correct answer: that — that after it's too bad introduces a factual noun clause.
8. They know ________________ he said to her.
Correct answer: what — what refers to the specific thing he said — a question word used as a noun.
9. They knew _______________ he did this.
Correct answer: that — that after knew introduces a factual noun clause.
10. I'm sorry. That's not _______________ I'm looking for.
Correct answer: what — what refers to the thing being looked for — not a factual statement.
Grammar review
Noun clauses: what vs. that
A noun clause is a dependent clause that acts as a noun, working as the subject, the object of a verb or preposition, or the complement. Noun clauses often begin with words like that, if, whether, what, who, when, where, why, and how.
The distinction this exercise tests: that and what can look interchangeable, but they play very different roles.
Use that when the clause is already complete: it has its own subject and verb, and nothing is missing:
I know that he is honest. (he is honest = complete on its own)
She said that she was tired.
Use what when something is missing from the clause: what itself fills that gap, meaning “the thing(s) that…”:
I'm interested in what he thinks. (he thinks ___; what fills the gap)
What you decide doesn't matter. (you decide ___; what is the missing object)
Quick test: try removing the word. If the rest of the clause still makes a complete sentence on its own, use that. If it doesn't (something's clearly missing), use what.
A noun clause is a dependent clause that acts as a noun, working as the subject, the object of a verb or preposition, or the complement. Noun clauses often begin with words like that, if, whether, what, who, when, where, why, and how.
The distinction this exercise tests: that and what can look interchangeable, but they play very different roles.
Use that when the clause is already complete: it has its own subject and verb, and nothing is missing:
I know that he is honest. (he is honest = complete on its own)
She said that she was tired.
Use what when something is missing from the clause: what itself fills that gap, meaning “the thing(s) that…”:
I'm interested in what he thinks. (he thinks ___; what fills the gap)
What you decide doesn't matter. (you decide ___; what is the missing object)
Quick test: try removing the word. If the rest of the clause still makes a complete sentence on its own, use that. If it doesn't (something's clearly missing), use what.
KEEP PRACTICING — MORE EXERCISES FOR YOU:
Noun clauses 1 (I)
Noun clauses 3 (I)
Adverb or noun clause? 1 (A)
What or that? 1 (I)
Adjective clauses 1 (I)
Noun clauses 1 (I)
Noun clauses 3 (I)
Adverb or noun clause? 1 (A)
What or that? 1 (I)
Adjective clauses 1 (I)
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