Interrogative adjectives
An interrogative adjective is a question word (what, which or whose) that is placed directly before a noun to ask about it, rather than replacing it. Unlike interrogative pronouns, interrogative adjectives always modify a noun, as in "Which train did you catch?", where "which" describes "train".
Types of interrogative adjectives
What
Asks about a general choice, thing or idea, often with no limited set of options.
e.g. What colour do you prefer?, What time does the meeting start?
Which
Asks about a choice from a specific, limited or known set of options.
e.g. Which shoes are yours?, Which route is faster?
Whose
Asks about possession or ownership of the noun that follows.
e.g. Whose keys are these?, Whose idea was it?
Rules to remember
- An interrogative adjective must always be followed directly by a noun; if there is no noun after it, the word is functioning as an interrogative pronoun instead.
- Use 'which' when the choice is limited to specific, known options, and use 'what' for open, general questions.
- Use 'whose' to ask about ownership, and note it does not change form for singular or plural nouns.
- Interrogative adjectives do not show agreement with the noun in number or gender; the same form is used regardless.
- Word order in questions typically follows: interrogative adjective + noun + auxiliary verb + subject + main verb.
Examples in sentences
| Example | How it works |
|---|---|
| What subject do you enjoy most at university? | 'What' modifies the noun 'subject' to ask an open question. |
| Which bus goes to the city centre? | 'Which' modifies 'bus', asking about a choice from known options. |
| Whose laptop is on the table? | 'Whose' modifies 'laptop' to ask about ownership. |
| What reasons did she give for leaving? | 'What' modifies the plural noun 'reasons', showing no change in form. |
| Which candidates were shortlisted for the job? | 'Which' modifies 'candidates', selecting from a specific group. |
| Whose signature do we need on this form? | 'Whose' modifies 'signature' to ask about ownership before a noun. |
Common mistakes
Incorrect: Which is your favourite?
Correct: Which book is your favourite? (add a noun after 'which' to make it an interrogative adjective, not a pronoun)
Incorrect: Whose is this bag?
Correct: Whose bag is this? (place 'whose' directly before the noun it modifies)
Incorrect: What book you like?
Correct: What book do you like? (include the auxiliary verb 'do' in the correct question order)
Why this matters for IELTS
In IELTS Speaking and Writing, examiners reward varied and accurate question forms under Grammatical Range and Accuracy. Confidently using interrogative adjectives such as 'which', 'what' and 'whose' before nouns, especially in Speaking Part 1 and 3 when clarifying or asking follow-up questions, shows structural control beyond basic yes/no questions and helps push your score towards band 7 and above.
Frequently asked questions
What is an interrogative adjective?
It is a question word, what, which or whose, placed directly before a noun to ask about that noun, such as in 'Which car is yours?'
What is the difference between an interrogative adjective and an interrogative pronoun?
An interrogative adjective is followed by a noun it modifies, like 'Which colour?', while an interrogative pronoun stands alone and replaces the noun, like 'Which is yours?'
Are what, which and whose the only interrogative adjectives?
Yes, these three words are the standard interrogative adjectives in English; words like 'who', 'why' and 'how' function differently and are not classed as interrogative adjectives.
Put your grammar to the test
Take a free IELTS practice test and get instant band scores with expert feedback.
Try a free Writing test