Interrogative Pronouns

Every question you ask because you don't know something has a small word doing the heavy lifting: Who approved this? What went wrong? Whose signature is that? Each opening word stands in for the very thing you're trying to find out — a placeholder for an answer that hasn't arrived yet. Those placeholders have a name, and getting to know them tidies up a surprising amount of everyday writing, from a chased email to a clean set of survey questions.

What they are

They're called interrogative pronouns — "interrogative" simply meaning asking, from the same root as interrogate. An ordinary pronoun stands in for a noun you already know (she, it, them); an interrogative pronoun stands in for one you don't — the answer. Ask What's the hold-up? and what holds the slot until the supplier turns up to fill it. That placeholder role is exactly what makes them pronouns. There are five: who, whom, whose, which and what.

The five

• who — a person, doing the action: Who signed off the budget?
• whom — a person on the receiving end: Whom did you notify? (more on this shortly — it's optional).
• whose — ownership: Whose account is this?
• which — a choice from a known set: Which of the two suppliers replied first?
• what — open, usually a thing: What caused the delay?

The gap between which and what is the width of the field. Which asks you to pick from a defined set — Which quarter was strongest? — while what throws it open — What should we do next year? The choice isn't cosmetic: the question word silently sets the kind of answer expected — a name, a thing, an owner, a selection — so reaching for the wrong one is how a question comes back answered sideways.

Why they earn their keep

That's the whole value of them: they let you aim a question at the exact missing piece rather than gesturing vaguely at it. A precise interrogative pronoun is the difference between What's the status? and a reply you can actually act on. It shows most in writing that has to be answered — a form, a brief, a set of interview questions. Who owns this action? pins a name; What's blocking it? pins a cause; Which option do we back? forces a choice. Vague question words invite vague answers, and a good deal of what gets called "poor communication" is really a question that never decided what it was asking.

Pronoun or determiner?

Here's the first thing that trips people. Which and what are interrogative pronouns only when they stand alone, being the missing thing themselves:

Which do you recommend? · What did the audit find?

Put a noun immediately after them and they change job — they become interrogative determiners, pointing words attached to a noun, exactly as the or my would:

Which supplier do you recommend? · What time suits you?

Same word, two roles. Alone, it is the unknown; with a noun, it's merely pointing at one. You needn't label it each time — just register whether it's standing on its own or leaning on a noun. The same split catches whose: Whose is this? (pronoun, standing alone) versus Whose bid came in lowest? (determiner, pointing at bid). Who and whom, by contrast, are always pronouns — you never get who person.

The same words, a different job

There's a second double life to know about. Who, whom, whose and which also serve as relative pronouns — the joining words that hang extra detail on a noun — where they ask nothing at all:

asking: Who chaired the meeting? · joining: the manager who chaired the meeting

The test is quick: if the word launches a question (a question mark is usually on its way), it's interrogative; if it's quietly gluing a description onto a noun, it's relative.

Watch out: whose vs who's

The classic red-pen error, because they're identical to the ear. whose is the belonging word; who's is only ever a contraction of who is (or who has):

• ✗ Who's laptop is this? → ✓ Whose laptop is this?
• ✓ Who's chairing today? — correct; it means who is chairing.

The test: if who is can replace it, you want who's; if not, whose.

And the whom question: whom is the form for a person on the receiving end (Whom did you appoint?), but it has quietly faded from ordinary use, and who is entirely acceptable — Who did you appoint? Keep whom for formal registers where its absence would be noticed, and drop it the moment it sounds starched.

Check Your Understanding

1. Pronoun or determiner: What evidence do we have?

2. Asking or joining: the auditor who flagged it?

3. Fix it: Who's remit does this fall under?

Where next

• What Is a Pronoun? — where the pronoun types fit together.
• Relative Pronouns: Who, Whom, Whose, Which, That — the same words doing their joining job.
• Personal Pronouns & Case (who/whom) — the who/whom case story in full.