Interrogative pronouns
An interrogative pronoun is a pronoun used to ask a question. The main interrogative pronouns in English are who, whom, whose, which and what. Each one replaces an unknown person, thing or choice that the question is trying to identify, for example: "Who called you?" or "Which do you prefer?"
Types of interrogative pronouns
Who
Asks about the subject of a sentence, referring to a person.
e.g. Who is knocking at the door?, Who wrote this letter?
Whom
Asks about the object of a verb or preposition, referring to a person; more formal than 'who'.
e.g. Whom did you meet?, To whom should I address this letter?
Whose
Asks about possession or ownership.
e.g. Whose bag is this?, Whose idea was it?
Which
Asks someone to choose from a limited or known set of options.
e.g. Which colour do you like?, Which of these books is yours?
What
Asks for information, a definition, or an open-ended choice with no limited set.
e.g. What is your name?, What happened last night?
Rules to remember
- Interrogative pronouns stand alone as the subject or object of the question; they do not describe a following noun (compare with interrogative adjectives such as 'which book').
- Use 'who' for the subject of a question and 'whom' for the object, especially in formal writing; in everyday speech 'who' is often used for both.
- Use 'which' when the choice is limited to a known set of items and 'what' when the possibilities are open or unknown.
- Place the interrogative pronoun at the start of the question, followed by the appropriate verb or auxiliary word order.
- 'Whose' shows possession and is always followed by a noun or stands alone when the noun is understood, for example: 'Whose is this?'
Examples in sentences
| Example | How it works |
|---|---|
| Who left this message on my desk? | 'Who' asks about the subject performing the action. |
| Whom did the manager promote last month? | 'Whom' asks about the object of the verb 'promote'. |
| Whose keys are these on the table? | 'Whose' asks about ownership of the keys. |
| Which of these two flights is cheaper? | 'Which' asks for a choice from a limited set of options. |
| What caused the delay this morning? | 'What' asks an open question about a cause or event. |
| To whom should I send my application? | 'Whom' follows a preposition, which is common in formal English. |
Common mistakes
Incorrect: Whom is calling you?
Correct: Who is calling you?
Incorrect: Which is your name?
Correct: What is your name?
Incorrect: Who's bag is this?
Correct: Whose bag is this?
Why this matters for IELTS
Using interrogative pronouns accurately, especially the correct distinction between 'who' and 'whom' and between 'which' and 'what', shows grammatical control that examiners reward under Grammatical Range and Accuracy. In IELTS Speaking Part 3 and Writing Task 2, forming clear indirect questions such as "I would like to know whose responsibility this is" also demonstrates flexible sentence structure, which can help push your band score higher.
Frequently asked questions
What is an interrogative pronoun?
It is a pronoun that asks a question, such as who, whom, whose, which or what, standing in for the unknown person or thing the question seeks to identify.
What is the difference between who and whom?
'Who' is used for the subject of a question (the doer of the action), while 'whom' is used for the object (the receiver of the action or the object of a preposition).
What is the difference between which and what?
'Which' is used when choosing from a specific, known set of options, while 'what' is used for open questions where the possible answers are not limited or known.
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