❓ Grammar · Questions & Negation
Subject vs Object Questions
Some questions need “do/does/did” and some don’t — learn to spot the difference in seconds.
Grammar › Questions & Negation › Subject vs Object Questions
The rule in one sentenceAsk about the subject (the doer) with no do/does/did — Who directed In the Earth? — but ask about the object (the receiver) with do/does/did — Who did Ben Wheatley direct in In the Earth?
What’s the difference?
Most English questions need an auxiliary verb — do, does, or did — placed before the subject: Did The Beach come out before High-Rise? But when the question word itself is asking about the subject of the sentence, that rule disappears completely. There’s no auxiliary and no inversion — the question keeps the exact word order of a normal statement.
The trick is working out what the question word is actually asking about. In Who kept watch over the hostages in Captain Phillips?, “who” is asking who did the watching — Somali pirates kept watch, so “who” replaces the subject, and the sentence stays in statement order: question word + verb. Compare that with Who did Godzilla (2014) cast as its human lead?, where Godzilla (2014) is already named as the subject and “who” is asking about the actor it cast — the object of the sentence. That question needs “did” and the usual inversion.
🎬 Compare: “Who directed Creed?” (subject question — Ryan Coogler directed it, no auxiliary needed) vs “Who did Ryan Coogler direct in Creed?” (object question — asking about the actor he cast, so “did” appears before the subject).
Same film, same director, completely different grammar depending on what the question word stands for.
A useful way to check: try answering the question with a name in place of the question word. If the answer sentence has exactly the same word order as the question — Who wrote the Percy Jackson books? → Rick Riordan wrote the Percy Jackson books — it’s a subject question. If you have to rearrange the sentence to answer it, or the question word clearly refers to something the subject acted on, it’s an object question and needs the auxiliary.
How to build it
Subject questions — no auxiliary
Who directed A Life Less Ordinary?
= A British filmmaker directed A Life Less Ordinary.What happened at the end of Warcraft?
Which studio made News of the World?
Object questions — auxiliary + inversion
Who did the soldiers fire on in Bloody Sunday?
What does Ari Aster usually direct?
Which real event does 22 July dramatise?
When to use which
Ask about the subject when…
- The question word is the doer: Who directed The Falling? (Carol Morley)
- You’re asking which person or thing did something: Which actor won an Oscar for Capote? (Philip Seymour Hoffman)
- No auxiliary is needed: just swap the question word into the subject’s spot.
Ask about the object when…
- The question word is the receiver: Who did Peter Strickland cast in In Fabric, and who did Joe Cornish cast in Attack the Block?
- You’re asking what someone made, chose, or said: What did Joe Cornish film in south London?
- You need do/does/did + subject + base verb, just like an ordinary question.
Quick test
🔍 Try answering your own question with a name instead of the question word. If nothing else about the sentence changes — Who wrote The Hunger Games? → Suzanne Collins wrote The Hunger Games — it’s a subject question. If you had to add do/does/did to make a natural answer, it’s an object question.
Visual guide
Teacher Teddy’s illustrated guide to this rule is being drawn — the full swipe-through infographic will appear here soon.
Common mistakes
❌ Who does directed Berberian Sound Studio?
✅ Who directed Berberian Sound Studio?
Subject questions never take an auxiliary at all — “does” and “directed” can’t sit together.
❌ Who did direct United 93?
✅ Who directed United 93?
“Who” is the subject (the director), so no “did” is needed here either.
❌ Who Monsters (2010) did cast as the photographer?
✅ Who did Monsters (2010) cast as the photographer?
Object questions need the auxiliary before the subject — you can’t skip the inversion.
❌ What Free Fire depicted that The Kid Who Would Be King avoided?
✅ What did Free Fire depict that The Kid Who Would Be King avoided?
“What” is the object here, so the sentence needs “did” plus the base verb “depict”.
Exceptions & tricky cases
1. Prepositions still go at the end. Object questions with a preposition keep it at the end in natural English — moving it to the front sounds overly formal.
✅ What is Sightseers based on? (An original screenplay by its stars — not “On what is Sightseers based?”)
2. “What” as the cause is still a subject. Even when a question word points to a cause rather than a person, if it’s grammatically the subject, skip the auxiliary.
✅ What made Grease so successful at the box office?
3. Short answers to subject questions still use “did”. The question itself has no auxiliary, but a short answer often adds one back in.
✅ “Who starred in Booksmart?” — “Kaitlyn Dever and Beanie Feldstein did.”
4. Multi-word subjects behave the same way. A whole phrase can be the subject, and it still takes no auxiliary.
✅ Which British actress has three Oscar nominations for acting? (Carey Mulligan does.)
Practice: subject or object question?
Eight quick questions. Pick the answer you’d actually say — you get the explanation either way.
1. ___ directed Green Zone?
“Who” is asking about the subject (the director) — so no auxiliary is needed. Unlike a Ben Wheatley film, Green Zone is a fact-based political thriller.
2. ___ Peter Strickland direct in Berberian Sound Studio?
“Who” here is the object (the actor Strickland cast) — object questions need do/does/did before the subject. (Dreams of a Life, directed by Carol Morley, takes a similarly meticulous approach to mood.)
3. What ___ at the end of The Duke of Burgundy?
“What” is the subject of “happened” — subject questions use normal statement word order, with no auxiliary.
4. Which studio ___ Godzilla (2014)?
“Which studio” is the subject doing the making — Legendary Pictures made Godzilla (2014), directed by Gareth Edwards — so skip do/does/did.
5. What ___ Charlie Kaufman write before Being John Malkovich?
“What” is the object of “write”, and the event is in the past, so this object question needs the past auxiliary “did”.
6. Which actor ___ an Oscar for Milk?
“Which actor” is the subject — Sean Penn won the Oscar — subject questions never take do/does/did.
7. Who ___ Peter Strickland cast as the sinister saleswoman in In Fabric?
“Who” is the object here (the actor Strickland chose), and the casting happened in the past, so this needs “did”.
8. ___ made The Creator so visually striking?
“What” is the subject of “made” here (the cause) — even asking about a cause, if the question word is the subject, skip the auxiliary.
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