What is a pronoun question in English?

It is a question whose question word stands alone as a pronoun: Who radioed? What happened? Which do you want? Whose is this? No noun follows the question word. If a noun follows (Which visor do you want?), you have an interrogative determiner instead.

When do I use who and when who did?

If who is the subject, there is no did: Who sealed the gate? If who is the object and the tense is present or past simple, add do, does, or did: Who did you radio? The same split applies to what and which: What happened? versus What did you pack?

Yes, in formal writing, especially after a preposition: To whom should I give the docket? In speech, who is the normal object form, and the preposition sits at the end: Who did you give the docket to? Whom is never the subject.

What is the difference between which and what in questions?

Which asks you to pick from a known set: Which do you want, the cracked visor or the spare? What asks in the open: What do you want from the foundry store? As pronouns they stand alone; as determiners they take a noun (which visor, what time).

Why is I don't know who did you radio wrong?

Because the question is embedded inside I don't know. Only the outer clause is a question, so the inner part returns to statement order and loses did: I don't know who you radioed. Who did you radio? is correct as a standalone question.

English grammar · Beginner

Pronouns in Questions: Who, What, Which, and Whose

Written by Eleanor Whitfield, Lead English Curriculum Editor · Reviewed September 2026

Pronoun questions use who, whom, what, which, and whose as the question word itself, with no noun after them: Who radioed? What happened? Which do you want? Whose is this? They are interrogative pronouns, not interrogative determiners. The determiner page covers which kiln and what time, where a noun follows. This page is the standalone set, including the subject/object split that decides whether do appears.

Who radioed the marina, and who did you radio?

who as subject in the first clause; who as object, so did appears, in the second

What it is

An interrogative pronoun is a question word that stands in for the unknown thing. Who stands for a person, what for a thing or an event, which for one of a known set, and whose for a possessor. Because the word is the whole noun phrase, nothing sits after it: Who signed the docket? not Who skipper signed. If a noun does sit after it, you have left this page and arrived at interrogative determiners (Which skipper signed?).

Who is on the winch? Which is on the winch? (Who asks for a person. Which asks you to pick from a set of things or people already in view.)

How to spot it

Find who, what, which, or whose at the front of a question with no noun immediately after it. Then ask whether that word is the subject of the verb (Who radioed?) or the object (Who did you radio?). Subject questions keep the statement verb and add no do. Object questions take the usual auxiliary-subject-verb order.

Who sealed the quarry gate? (who is the subject of sealed; no did)
Who did you radio? (you is the subject; who is the object; did appears)
What happened on the millrace? (what is the subject of happened)
Whose is this visor? (whose stands alone as a pronoun)

Which as a pronoun needs a set in the context: two visors on the hook, Which do you want? Without a set, what is the open question: What do you want?

Pronouns in Questions Quick Reference

Standalone question pronouns

Pronoun	Stands for	Subject example	Object example
who	a person	Who radioed?	Who did you radio?
whom	a person as object, formal	(rare as subject)	Whom did you radio?
what	a thing, an event, or an open choice	What happened?	What did you pack?
which	one of a known set	Which is heavier?	Which do you want?
whose	a possessor	Whose is this?	Whose did you borrow?

Common Pronouns in Questions Examples in English

The split that matters is subject versus object. The choice of word is the second split:

Who as Subject and Object

Who radioed the marina?: who is the subject; radioed stays past
Who is working the night winch?: who is the subject of is working
Who did you radio from the jetty?: who is the object; did plus bare radio
Who are you waiting for?: who is the object of for, preposition at the end

Who called you? (someone called you) versus Who did you call? (you called someone). The auxiliary is the whole of the test.

What as Subject and Object

What happened on the millrace?: what is the subject of happened
What went wrong with the winch?: what is the subject of went
What did you pack in the visor case?: what is the object of pack
What are you looking at?: what is the object of at

What as subject takes a singular verb in the default: What is on the hook? even if the answer might be plural.

Which and Whose Alone

Which do you want, the cracked visor or the spare?: which as a pronoun, set in view
Which is nearer, the quarry or the marina?: which as subject, still a closed set
Whose is this docket?: whose as a pronoun, no noun after it
Whose did you borrow for the night shift?: whose as object, meaning whose visor or whose charts

Whose visor is this? is the determiner. Whose is this? is the pronoun. Both are correct; the noun is either said or recovered.

Embedded Pronoun Questions

I don't know who radioed.: statement order inside; who is still the subject
Can you tell me who you radioed?: no did inside; statement order
She asked what had happened on the millrace.: reported, past perfect optional
We wondered which they would take.: which as object, statement order

Once the question sits inside another clause, inversion and do disappear. Who did you radio becomes who you radioed after I don't know.

How Pronouns in Questions Work

Pick the pronoun, then decide whether it is the subject. That second decision controls do.

No Noun After a Pronoun

Who, what, which, and whose as pronouns are the whole noun phrase. A noun after them turns them into determiners: which visor, what time, whose docket. The rest of the question (auxiliary, subject, verb) is the same system as any other question.

Which do you want? Which visor do you want?

pronoun; then determiner plus noun

No noun after it: this page.

Subject Pronouns Skip Do

If the question word is the subject, there is nothing to invert. The verb stays in its statement form: Who sealed the gate? What happened? Which is heavier? Adding did here is the error this page exists to stop: Who did seal the gate? only appears with a stressed did meaning who actually sealed it.

Who sealed the quarry gate? What happened on the millrace?

subject questions, no did

Wh-word as subject: statement verb.

Object Pronouns Take Ordinary Question Order

If someone else is the subject, the question word is an object or a complement, so you invert: Who did you radio? What did you pack? Which do you want? Whose did you borrow? The same order holds with be and with modals: Who are you waiting for? What can we take?

Who did you radio? What can we take?

did and can in front of the real subject

Wh-word as object: auxiliary first.

Which Needs a Set; What Opens the Field

Which as a pronoun points at a limited choice the listener can see or has just heard. What as a pronoun asks in the open. Which do you want? with two visors on the hook. What do you want? with no list. Using which with no set sounds as if a list was mentioned and missed.

Which do you want, the cracked visor or the spare? What do you want from the foundry store?

closed set with which; open request with what

Which = a set. What = open.

Common Mistakes with Pronouns in Questions

Incorrect: Who did seal the quarry gate?

Correct: Who sealed the quarry gate?

Who is the subject, so did is not added and sealed keeps its past form. Did would only appear for emphasis (Who did seal it, then?), which is a different sentence.

Incorrect: Who you radioed from the jetty?

Correct: Who did you radio from the jetty?

Who is the object and you is the subject, so the question needs did and the bare verb. Leaving both the auxiliary out and the statement order in produces a fragment.

Incorrect: Whom sealed the quarry gate?

Correct: Who sealed the quarry gate?

Whom is an object form and cannot be the subject of sealed. Who is the only choice in a subject question about a person.

Incorrect: Which visor do you want which?

Correct: Which do you want, the cracked visor or the spare?

A pronoun question does not also keep the noun in the same slot. Either use the determiner (Which visor do you want?) or the pronoun (Which do you want?).

Whom, and Prepositions at the End

Whom is the object form of who. Everyday English keeps who and puts the preposition at the end.

Whom in careful style

Whom appears as an object, especially after a fronted preposition: To whom did you radio? Whom did you meet?

Whom did you radio?: formal object who
To whom should I give the docket?: preposition plus whom
With whom did you wait on the jetty?: formal, preposition fronted

Who did you radio? is the normal spoken form. Whom is never a subject: Whom sealed the gate? is wrong.

Preposition at the end

The everyday pattern keeps who or what and strands the preposition.

Who are you waiting for?: for at the end
What is the visor made of?: of at the end
Who did you give the docket to?: to at the end, who not whom

This is standard English. Moving the preposition to the front without switching to whom (To who did you give it?) is the version that sounds mixed.

Quick Check: Pronouns in Questions

Choose the pronoun question, and decide whether do is needed.

1. ___ sealed the quarry gate? (Who / Who did)

Answer: Who

subject question, no did

2. ___ you radio from the jetty? (Who / Who did)

Answer: Who did

object question, did plus bare radio

3. ___ happened on the millrace? (What / What did)

Answer: What

what is the subject of happened

4. ___ is this visor? (Whose / Whose visor)

Answer: Whose

pronoun; Whose visor is this? would be the determiner

5. I don't know ___ you radioed. (who / who did)

Answer: who

embedded: statement order, no did

Pronouns in Questions FAQs

What is a pronoun question in English?: It is a question whose question word stands alone as a pronoun: Who radioed? What happened? Which do you want? Whose is this? No noun follows the question word. If a noun follows (Which visor do you want?), you have an interrogative determiner instead.
When do I use who and when who did?: If who is the subject, there is no did: Who sealed the gate? If who is the object and the tense is present or past simple, add do, does, or did: Who did you radio? The same split applies to what and which: What happened? versus What did you pack?
Is whom still used?: Yes, in formal writing, especially after a preposition: To whom should I give the docket? In speech, who is the normal object form, and the preposition sits at the end: Who did you give the docket to? Whom is never the subject.
What is the difference between which and what in questions?: Which asks you to pick from a known set: Which do you want, the cracked visor or the spare? What asks in the open: What do you want from the foundry store? As pronouns they stand alone; as determiners they take a noun (which visor, what time).
Why is I don't know who did you radio wrong?: Because the question is embedded inside I don't know. Only the outer clause is a question, so the inner part returns to statement order and loses did: I don't know who you radioed. Who did you radio? is correct as a standalone question.