Grammar for Teachers
Grammar for Teachers
🟡 Intermediate

Questions: Subject Questions — When There Is No Inversion

What this session covers

There is one important situation in English where questions do NOT use inversion — where the word order looks exactly like a statement. This happens when the question word (who or what) is asking about the subject of the sentence. Understanding why this happens — and teaching it clearly — resolves one of the most puzzling areas of English question formation.

Personal Reflection

Before you start — think honestly about your own teaching and experience.

Q1
How confident do you feel explaining subject questions — and why 'Who wrote this?' uses no auxiliary while 'Who did you see?' does?
Q2
Which of these have you experienced? (Select all that apply)

Discover the Pattern

Look at the examples. Answer each question before reading the explanation — this is how your students will learn too.

1

Read these pairs of questions. Both use 'who'. But something is different about their structure. Can you find it?

Who did you see at the meeting? (object question)
Who came to the meeting? (subject question)
Who does she teach? (object question)
Who teaches the senior class? (subject question)
Who did they invite? (object question)
Who invited them? (subject question)
What is structurally different between each pair? Which question has an auxiliary verb? Which does not?

Object questions (left column): have an auxiliary verb (did, does). The question word 'who' is asking about the object — the person who received the action. 'Who did you see?' — 'you' is the subject. 'Who' is what you saw (the object). Subject questions (right column): have NO auxiliary verb. The question word 'who' is the subject. 'Who came to the meeting?' — 'who' IS the subject doing the action. Because 'who' is already in the subject position, there is nothing to invert. The sentence works like a statement in terms of word order: who (subject) + verb + rest. This is why 'Who came?' looks like a statement — because structurally, the subject has just been replaced by a question word.'

2

Now look at these sentences. Some are statements, some are questions. Notice the word order in each.

Maria wrote this letter. (statement)
Who wrote this letter? (subject question)
She spoke to the headteacher. (statement)
Who spoke to the headteacher? (subject question)
Something happened at the school. (statement)
What happened at the school? (subject question)
What is the relationship between the statement and the subject question? What has simply been replaced?

In each case, the subject of the statement has been replaced by the question word. 'Maria' → 'Who'. 'She' → 'Who'. 'Something' → 'What'. The rest of the sentence stays identical — the verb and the rest of the sentence are unchanged. This is the clearest way to teach subject questions: imagine replacing the subject with 'who' or 'what' — everything else stays the same. No auxiliary is needed because the subject is the only thing being questioned, and the verb already has a third person singular form ('wrote', 'spoke', 'happened') that matches the question word as subject.'

3

Now read these test sentences. Some are subject questions and some are object questions. Can you tell them apart?

Who did the teacher help?
Who helped the teacher?
What surprised everyone?
What did everyone say?
Who gave you this book?
Who did you give the book to?
For each sentence: who or what is performing the action? Who or what is receiving the action? Use this to decide whether it is a subject or object question.

'Who did the teacher help?' — the teacher is performing the action (helping). 'Who' is receiving the help (object). Object question — uses did. 'Who helped the teacher?' — 'who' is performing the action (helping). Subject question — no did, no inversion. 'What surprised everyone?' — 'what' is causing the surprise (performing the action). Subject question — no auxiliary. 'What did everyone say?' — everyone is speaking (performing). 'What' is being said (object of saying). Object question — uses did. A simple diagnostic test: replace the question word with a noun and see if it becomes the subject of the sentence. 'Who helped the teacher?' → 'Maria helped the teacher.' Maria is the subject. So 'who' is the subject. Subject question — no auxiliary needed.'

The Pattern — What You Just Discovered

Subject questions are formed when who or what replaces the subject of the sentence. In this case, no auxiliary verb is needed and there is no inversion — the word order is the same as a statement. Object questions are formed when who or what asks about the object — a different person or thing receives the action. Object questions use the normal auxiliary + inversion structure.
Tense / FormUse / MeaningExampleKey time words
Object question Who/what is the object — another word is the subject Who did Maria help? (Maria = subject, who = object) Uses auxiliary + inversion
Subject question Who/what is the subject — asking who/what did the action Who helped Maria? (who = subject, Maria = object) No auxiliary, no inversion
Object question What asks about the object of the verb What did they discuss? (they = subject, what = object) Uses auxiliary + inversion
Subject question What asks about the subject of the verb What happened at the school? (what = subject) No auxiliary, no inversion
Special Rule / Notes

THE DIAGNOSTIC TEST — subject or object question?

Step 1: Imagine replacing the question word with a real noun.
Step 2: Ask: is that noun the SUBJECT (doing the action) or the OBJECT (receiving the action)?
Subject → no auxiliary, no inversion (subject question)
Object → auxiliary + inversion (object question)

'Who taught you English?'
Replace: 'Maria taught you English.' → Maria = subject (doing the teaching).
Conclusion: Who = subject → no auxiliary needed. ✓ 'Who taught you English?' is correct.
'Who did you teach?'
Replace: 'You taught Maria.' → Maria = object (receiving the teaching). You = subject.
Conclusion: Who = object → needs auxiliary. ✓ 'Who did you teach?' is correct.
'What broke the window?'
Replace: 'A stone broke the window.' → stone = subject.
Conclusion: What = subject → no auxiliary. ✓ 'What broke the window?' is correct.

COMMON CONFUSION — present tense subject questions:
In the present tense, subject questions with non-be verbs keep the third person -s:

'Who teaches this class?' — 'who' is subject, so 'teaches' keeps -s (agreeing with singular who).
'What causes this problem?' — 'what' is subject, 'causes' keeps -s.
This can surprise students who have been told 'never use -s in a question'. The rule is: -s disappears when does is used (object questions). When there is no auxiliary (subject questions), the verb keeps its normal third person form.
🎥

Is the question word asking about the person or thing DOING the action? → subject question — no auxiliary, no inversion. Is the question word asking about the person or thing RECEIVING the action? → object question — use auxiliary + inversion. Replace the question word with a name: if that name is the subject, it is a subject question. If that name is the object (and another word is the subject), it is an object question.

Common Student Errors

Who did write this letter?
Who wrote this letter?
Why'Who' is the subject — it is asking who performed the writing. Subject questions do not need an auxiliary. 'Did' is unnecessary and wrong here. Remove it: 'Who wrote this letter?' The verb keeps its past tense form because there is no 'did' to carry it.
What did happen at the meeting?
What happened at the meeting?
Why'What' is the subject of 'happen' — asking what event occurred. Subject question: no auxiliary, no inversion. Remove 'did'. 'What happened?' is correct.
Who teaches this class, does?
Who teaches this class?
WhyNo auxiliary is needed in a subject question. The verb 'teaches' keeps its -s because 'who' is the subject (singular). Adding 'does' at the end is wrong — it is not needed.
Who you spoke to at the meeting?
Who did you speak to at the meeting?
WhyHere 'you' is the subject (doing the speaking) and 'who' is the object (the person spoken to). This is an OBJECT question — it needs an auxiliary and inversion: 'Who did you speak to?' This is the opposite of a subject question.
What does happen when it rains?
What happens when it rains?
Why'What' is the subject of 'happens' — asking what event occurs. Subject question: no auxiliary. The verb 'happens' keeps its -s to agree with 'what' as a singular subject. Remove 'does'.

Check Your Understanding — Part 1

Choose the correct form. Decide first: is 'who' or 'what' the subject or the object? Then choose accordingly.

Who ___________ the door open? Someone left it open all night.
Who ___________ you see at the training last week?
What ___________ the most useful thing you learned from that session?
Who ___________ you that information?
What ___________ in the meeting yesterday — can you tell me?
0 / 5 answered

Check Your Understanding — Part 2: Why Is It Wrong?

Each question contains an error. Write the correct version and explain whether it is a subject or object question — then reveal the answer.

Who did win the competition last year?
Write the correct sentence:
Explain why it is wrong:
Who won the competition last year?
Subject question — 'who' is asking about the person who won (the subject, the performer of the action). Subject questions do not use an auxiliary. Remove 'did'. The verb 'won' stays in past form because there is no auxiliary to carry the tense.
What does cause the flooding every year?
Write the correct sentence:
Explain why it is wrong:
What causes the flooding every year?
Subject question — 'what' is asking about the cause (the subject performing the action of causing). No auxiliary needed. The verb 'causes' keeps its -s because 'what' is the subject and takes third person singular agreement. Remove 'does'.
Who you spoke to about the problem?
Write the correct sentence:
Explain why it is wrong:
Who did you speak to about the problem?
Object question — 'you' is the subject (doing the speaking). 'Who' is the object (the person spoken to). Object questions need an auxiliary and inversion: 'Who did you speak to?' Note: 'speak' returns to base form after 'did'.
What happens in the story?
Write the correct sentence:
Explain why it is wrong:
What happens in the story?
This sentence is actually CORRECT. 'What' is the subject of 'happens'. Subject question: no auxiliary, verb keeps -s ('happens'). Students sometimes doubt this sentence because it looks like a statement — but it is a correctly formed subject question.

Classroom Teaching Sequence

Use this sequence directly in class — guided discovery, no textbook needed. Tap each step to mark it done.

0 / 5 done
1

STEP 1 — THE PUZZLE (5 minutes): Write these two questions on the board:

'Who did Maria help?'
'Who helped Maria?'
Ask: what is different? Which has 'did'? Which doesn't? Are both correct? Establish: yes, both are correct English — but they ask different things. The first asks about the person Maria helped. The second asks about the person who helped Maria. One question has 'did'. The other doesn't. Why?
2

STEP 2 — REPLACE THE SUBJECT (8 minutes): Teach the diagnostic test. Write five statements with clear subjects.

'Maria wrote the letter.' Ask: what question would you form if you wanted to know who wrote it? 'Who wrote the letter?' — replace Maria with who. Maria was the subject. Who = subject. No auxiliary needed.
'She saw Maria at the market.' Ask: what question asks who she saw? 'Who did she see at the market?' — Maria was the object, she is the subject. Object question — needs did.
Drill five more. Students identify subject/object before forming the question.
3

STEP 3 — THE -S SURPRISE (5 minutes): Write:

'Who teaches this class?' Ask: why does 'teaches' keep its -s? Haven't we learned that questions don't have -s? Explain: the -s disappears only when 'does' is added (because does carries the third person signal). In subject questions, there is no does — so the verb keeps its normal form. 'Who teaches' = 'who' is the subject, verb agrees with it. This is a good moment to deepen understanding of WHY the rules work, not just WHAT the rule is.
4

STEP 4 — CONTRASTING PAIRS (5 minutes): Give students pairs of questions and ask them to explain the difference in meaning and structure.

'Who did the students thank?' vs. 'Who thanked the students?'
'What did the news report?' vs. 'What shocked people?'
'Who do you trust?' vs. 'Who trusts you?'
Discuss: what changes structurally? What changes in meaning?
5

STEP 5 — STUDENT PRODUCTION (5 minutes): Give students a simple narrative.

'A student found a bag in the classroom. She gave it to the headteacher. The headteacher called the parents.'
Students generate subject questions about the narrative:
'Who found the bag?' / 'Who did she give it to?' / 'Who called the parents?'
Listen for 'Who did find?' errors and correct immediately.

Ready-to-Use Classroom Materials

Use directly in class — copy, adapt, or read aloud. No printing needed.

1 Subject or Object? — Diagnosis Activity (No materials)
Read each question aloud. Students call out: SUBJECT question (no auxiliary) or OBJECT question (with auxiliary). They must give a reason: 'who/what is doing the action' or 'who/what is receiving the action'. This builds the analytical skill, not just the rule.
Example sentences
Who taught you how to read? → SUBJECT (who = the teacher = subject)
Who did you teach? → OBJECT (you = subject, who = the person taught = object)
What broke the window? → SUBJECT (what = the thing that broke = subject)
What did you break? → OBJECT (you = subject, what = the thing broken = object)
Who arrived late? → SUBJECT
Who did the headteacher call? → OBJECT
2 Replace the Subject — Guided Production (No materials)
Read each statement. Students identify the subject and replace it with 'who' or 'what' to form a subject question. This makes the rule concrete — subject questions are just statements with the subject replaced by a question word.
Example sentences
Maria told the class about the new rules. → Who told the class about the new rules?
Something frightened the children. → What frightened the children?
A parent came to the school early this morning. → Who came to the school early this morning?
The storm damaged the classroom roof. → What damaged the classroom roof?
An older student helped the new children find their classroom. → Who helped the new children find their classroom?
3 Error Hunt — Dictation (No materials)
Dictate these questions. Students find and correct errors. Some sentences are correct. Discuss the rule behind each.
Example sentences
Who taught you to read? ✓
Who did teach the senior class yesterday? ✗ → Who taught the senior class yesterday?
What does happen when the rains come? ✗ → What happens when the rains come?
Who did you speak to this morning? ✓
What caused the fire? ✓
Who did win the school competition? ✗ → Who won the school competition?

Plan Your Next Steps

For each strategy, choose the option that best describes where you are now.

Teach the diagnostic test (replace the question word with a name — is it the subject or object?) as the primary strategy
Use contrasting pairs consistently — students who see both question types side by side learn the distinction faster
Address the -s surprise explicitly — it contradicts what students have previously learned about questions and needs explanation
Connect subject questions to real narratives — stories with clear actions and actors generate subject questions naturally
This lesson is the conceptual foundation for indirect questions (the next lesson) — understanding subject/object position makes indirect questions much easier
What is the one change you will make next time you teach this grammar point?

Key Takeaways

1 Subject questions ask who or what is performing the action. They do NOT use an auxiliary verb and do NOT invert — the word order looks like a statement
2 Object questions ask who or what receives the action. They use auxiliary + inversion — the normal question structure
3 Diagnostic test: replace the question word with a name. If that name is the subject → no auxiliary (subject question). If another word is the subject → use auxiliary + inversion (object question)
4 In present tense subject questions, the verb keeps its -s: 'Who teaches this class?' — 'teaches' agrees with 'who' as subject
5 'What happened?' and 'Who came?' are subject questions — correct even though they look like statements