What is an interrogative adjective?
Which, what, and whose are questions words. When they ask about a noun, they’re being used as interrogative adjectives. Let’s learn more.
– Interrogative just means “questioning” or “related to a question.”
– Adjectives are words that describe or modify nouns.
So, interrogative adjectives are question words that come right before a noun and ask for more information about it. Not all question words are interrogative adjectives—only the ones that are directly attached to a noun.
The three interrogative adjectives: which, what, whose
In English, there are only three interrogative adjectives:
- Which
- What
- Whose
1. Which
Which is used when the range of possible answers is limited or already known to the speaker and listener.
- Which book did you borrow from the library?
- Which color do you prefer: blue or green?
- Which way should we go?
“Which” comes directly before a noun (book, color, way) and specifies something particular.
2. What
What is broader—it’s used when the possible answers are not limited or when the speaker doesn’t know the options.
- What movie are we watching tonight?
- What subject do you like most at school?
- What time is the meeting?
Again, “what” comes right before a noun (movie, subject, time) and is asking about the identity or quality of that noun.
3. Whose
Whose is the possessive interrogative adjective. It asks about ownership or association.
- Whose jacket is this?
- Whose idea was it to order pizza?
- Whose phone keeps ringing?
“Whose” modifies a noun by asking to whom it belongs.
Interrogative adjectives vs. interrogative pronouns
This is where most learners (and even some native speakers!) get tripped up. Let’s clarify the difference:
- Interrogative adjectives: always come before a noun and modify it.
- Interrogative pronouns: stand alone and do not modify a noun.
| Interrogative Adjective | Interrogative Pronoun |
|---|---|
| Which book is yours? | Which is yours? |
| What color do you want? | What do you want? |
| Whose bag is missing? | Whose is missing? |
If there’s a noun immediately after the question word, it’s an interrogative adjective. If the word stands alone, it’s a pronoun.
How do interrogative adjectives work in a sentence?
Interrogative adjectives are always used in questions and must be followed by the noun they describe. You can use them to ask for specific information, to clarify, or to make a selection.
- Which route is the fastest?
- What recipe are you using?
- Whose dog barked all night?
Note: The noun comes right after the interrogative adjective—there’s no other word in between.
Common mistakes and how to avoid them
Mistake 1: Using an interrogative pronoun instead of an adjective
Incorrect: Which do you want car?
Correct: Which car do you want?
Mistake 2: Using “who” or “whom” as an interrogative adjective
Who and whom are never interrogative adjectives—they are only pronouns. They do not directly modify nouns.
Incorrect: Who book is this?
Correct: Whose book is this?
Quick Reference Table
| Interrogative Adjective | Example Question | Noun Modified |
|---|---|---|
| which | Which dress should I wear? | dress |
| what | What flavor do you want? | flavor |
| whose | Whose keys are these on the table? | keys |
Why does it matter?
Understanding interrogative adjectives helps you:
- Ask more precise questions
- Avoid common grammar mistakes (like confusing adjectives with pronouns)
- Sound more natural and fluent in English conversations
If you’re learning English, interrogative adjectives make your questions clearer and your writing more precise.
Practice: Try it yourself!
Rewrite the following sentences using interrogative adjectives:
- (You want to know which train to take)
Which train should I take to the airport? - (You want to know what song is playing)
What song is playing right now? - (You want to know who owns the bicycle)
Whose bicycle is this?
Interrogative adjectives in real life
You use these every day—ordering food, making plans, or just chatting:
- What pizza toppings do you like?
- Which seat is mine?
- Whose turn is it to do the dishes?
See? You’re already an expert.
Related topics
- Interrogative Pronouns: What’s the Difference?
- Demonstrative Adjectives: This, That, These, Those
- Possessive Adjectives: My, Your, His, Her, Our, Their
Summary
Interrogative adjectives—which, what, whose—are question words that modify nouns. They help you ask clear, direct questions about people, places, things, and ownership. Remember: if the question word comes right before a noun, it’s probably an interrogative adjective.
Keep practicing, and you’ll “know” them inside out!
Sources:
Merriam-Webster: Interrogative Adjective
Grammarflex: Interrogative Adjectives
Cambridge Dictionary: Interrogative Adjectives
