B1Questions

Subject Questions

What is it?

In most English questions, we ask about the object or another part of the sentence, and we need to add an auxiliary verb (do/does/did). But when we ask about the SUBJECT itself — the person or thing performing the action — we use "who" or "what" directly in the subject position, and no auxiliary verb is needed. These are called subject questions.

How to form it

Subject	Positive	Negative	Question
Object question (needs auxiliary)	What did she eat? (she = subject, we ask about object)		Who did you call?
Subject question (no auxiliary)	Who ate the cake? (we ask about the subject)		What happened?
Present simple — subject question	Who lives next door?	Who doesn't agree?	What makes you happy?
Past simple — subject question	Who called last night?		What went wrong?
Present perfect — subject question	Who has sent me a message?		What has changed?

• Subject question: "Who/What" + verb (+ object). No auxiliary, no inversion.
• Object question: "Who/What" + auxiliary + subject + main verb.
• Test: can you replace "who/what" with a subject pronoun (he/she/it/they)? If yes → subject question.
• In subject questions, verbs in the third person still take their normal form: "Who lives here?" (not "who live").
• "Who" asks about people. "What" asks about things or actions.
• Compare: "Who did you see?" (object question — you is the subject) vs "Who saw you?" (subject question — who is the subject).

When to use it

1
Subject question: "who/what" replaces the subject
Who broke this window? (someone broke it)
2
Object question: "who/what" replaces the object
What did you break? (you broke something)
3
No "do/does/did" in subject questions
Who told you? (NOT: Who did tell you?)
4
Present simple: third-person -s on verb in subject questions
Who lives next door?
5
"What" as subject for things/events
What causes most accidents on this road?

Common mistakes

Who did call you?

Who called you?

Subject question — no auxiliary needed. "Who" is the subject performing "called".

Who did win the match?

Who won the match?

Subject question — "who" is the subject of "won". No "did" is needed.

What does happen here?

What happens here?

Subject question — "what" is the subject of "happens". No "does" is needed.

Quick reference

Subject question: "who/what" is the SUBJECT of the verb.
No auxiliary (do/does/did) needed.
Word order: Who/What + verb (+ object/rest).
Object question: "who/what" asks about the OBJECT — needs auxiliary.
Test: try replacing "who/what" with "somebody/something" in a statement. If it works naturally → subject question.
Third-person -s still applies: "Who wants coffee?" not "Who want coffee?"

Natural conversation example

Two friends discuss office gossip.

Bex

Did you hear? Someone locked the kitchen by mistake.

Glen

Who locked it? I couldn't get my lunch!

Bex

No idea. And something spilt in the lift this morning.

Glen

What spilt? It smells terrible in there.

Bex

I think someone left a coffee. Whoever did it hasn't owned up.

Glen

What happened at the team meeting? I had to miss it.

Bex

Not much. Who normally chairs those meetings?

Glen

Usually Sarah. But who knows what happens in there.

Practice Exercises

Write a subject question using "who" or "what" for the underlined part.

1.
Someone called me last night.
2.
Something made a loud noise.
3.
Somebody left this bag here.
4.
Something happened at 3am.
5.
Someone has eaten my sandwich!
6.
Something is burning.
7.
Someone told her the secret.
8.
Something changed everything.
9.
Someone has taken the keys.
10.
Something caused the delay.

Questions (overview)All Topics Indirect Questions

Now use Subject Questions in real conversation

Grammar sticks when you use it out loud. Practise with an AI tutor who gives you instant feedback.

Speak with AI Tutor