An interrogative determiner is a word that modifies a noun by asking a question. Interrogative determiners were called "interrogative adjectives" in traditional grammar.
There are three interrogative determiners in English:
· What – asking a question about a thing or things
· Which – asking a question about a thing or things
· Whose – asking a question about possession
Notice that in the following examples, 'what' is a pronoun, not a determiner.
1. What do you do for a living?
2. What is your name?
Note: Do not confuse “whose” and “who’s”. We use “whose” to ask a question about a possession.
Incorrect- who’s book is this?
Correct- whose book is this?