Grammar
Subject and object questions: understand the difference
Ask who does the action first. If who is the subject, the question keeps statement order: Who sent the message? If who receives the action, use normal question order: Who did you message?
Form subject and object questions with the correct question word order and auxiliary verb.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
Who did you invite to the meeting? /huː dɪd juː ɪnˈvaɪt tə ðə ˈmiːtɪŋ/
The short answer
In a subject question, the question word is the subject, so do not use do, does, or did with an ordinary verb. In an object question, the question word is the object. Use the usual question order: question word, auxiliary verb, subject, and main verb.
Who opened the window?
Why it works: Who does the action, so it is the subject. The question does not need did.
5 more examples
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Who organized the meeting?
Who is the person who did the organizing. It is the subject of the question.
Not this:
Who did the manager organizethe meeting for? What changes: Here, who is the person who receives the action, so the question uses did before the subject manager. -
What caused the delay?
What names the unknown cause. It is the subject, so caused follows it directly.
Not this:
What did the delay cause? What changes: What is the object in this question, so did comes before the subject the delay. -
Which employee works from home on Fridays?
Which employee is singular and is the subject. The present simple verb has -s.
Not this:
Which employee do you meeton Fridays? What changes: Which employee is the object of meet, so do comes before the subject you. -
Who is speaking to the client?
Who is the subject of the present continuous verb phrase.
Not this:
Who is the client speakingto? What changes: The client is the subject. Who is the object of the preposition to. -
How many people joined the call?
How many people is the plural subject, so joined follows it without did.
Not this:
How many people did the host invite? What changes: How many people is the object of invite, so the question uses did and the base verb invite.
Read the full guide
Start with the answer you would expect. If the answer is the person or thing doing the action, make a subject question. If the answer is the person or thing affected by the action, make an object question. Then check whether you need an auxiliary verb before the subject.
Find the action first
Read the statement and find the action. Then ask who or what performs that action. That person or thing is the subject. Ask who or what receives or is affected by the action. That person or thing is the object.
The technician fixed the printer.
The technician does the action, so the technician is the subject. The printer receives the action, so it is the object.
Use statement order for subject questions
In a subject question, who, what, which noun, or how many replaces the subject. The unknown subject comes first, followed by the verb. Do not add do, does, or did before an ordinary verb because the question word already fills the subject position.
Who delivers the packages each morning?
Who is the singular subject, so delivers has the present simple ending.
Make a subject question from: Someone left this note.
Write Who left this note? Who is the subject, so left follows it directly.
Use normal question order for object questions
In an object question, the question word replaces the object. The subject is still named in the question, so use the usual question pattern. With an ordinary present or past verb, put do, does, or did before the subject.
Who did the technician call?
The technician is the subject. Who is the object of call, so did comes before the technician.
Make an object question from: The technician called someone.
Write Who did the technician call? Use did because the question is about a past action.
Choose do, does, or did carefully
Use do with I, you, we, and they in present-simple object questions. Use does with he, she, it, and a singular noun. Use did for past-simple object questions with any subject. After do, does, or did, keep the main verb in its base form.
What does the new assistant need?
Does agrees with the singular subject the new assistant. Need stays in the base form.
What did the visitors bring?
Did marks past time, so bring does not change to brought in the question.
Keep the subject after be, have, and modal verbs
Object questions with be, have, or a modal verb do not use do, does, or did. Put the auxiliary verb before the subject, as in other questions. A subject question still begins with the question word followed by the verb.
Who has completed the survey?
Who is the subject, so has comes directly after it.
Who has the supervisor contacted?
The supervisor is the subject, so has comes before the supervisor in this object question.
Check questions with which and how many
Which and how many can introduce subject or object questions. Look at the noun phrase after them. If it does the action, use subject-question order. If another subject does the action, use object-question order.
Which route reaches the airport fastest?
Which route is the subject because the route reaches the airport.
Choose the correct question: Which route reaches the airport fastest? or Which route does the driver take?
Both are correct, but they ask for different roles. The first asks for the route that does the reaching. The second asks for the route that the driver takes.
Before you go
Remember this
Find the action and ask who or what does it. Use statement order for a subject question: Who called? For an object question, use normal question order: Who did you call? Check the tense and the auxiliary verb after you identify the role of the question word.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
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Try the written questionsQuestions about "Subject and object questions: understand the difference"
What is a subject question?
A subject question asks who or what performs an action. The question word is the subject, so it is followed directly by the verb. For example, Who wrote the report? asks for the person who wrote it.
Who organized the meeting?
What is an object question?
An object question asks who or what receives an action. The original subject stays in the question. For example, Who did the editor thank? asks for the person who received the thanks.
Who did the manager organize the meeting for?
Why do subject questions not use do or did?
In a subject question, who or what already takes the subject position. With an ordinary verb, English follows it with the verb: What changed the schedule? Do, does, and did are used when another subject remains in the question.
What caused the delay?
How can I tell whether who is a subject or an object?
Find the named subject and the action. If who does the action, it is the subject. If another person does the action to who, it is the object. Compare Who called the office? with Who did the office call?
What did the delay cause?
Can which and how many begin subject questions?
Yes. Which and how many can be part of the subject when the following noun performs the action. They can also introduce an object question when another subject performs the action. Check who or what does the verb before you choose the word order.
Which employee works from home on Fridays?