Forming Subject and Object Questions in Present and Past Tenses

Hello again. In the previous lesson, you practised choosing future forms according to meaning: will for decisions and predictions, going to for intentions or visible evidence, the present continuous for arrangements, and the present simple for schedules.

Now we will focus on a question pattern that makes a major difference in everyday conversations: the difference between subject questions and object questions. Both can begin with who or what, but their word order is different. By the end of this lesson, you will be able to ask accurately about people, things, places, and events in common present and past tenses.

---

Start with the missing information

A sentence usually has a subject: the person or thing that does, causes, or experiences an action.

Nadia sent an email.
The bus arrived late.
Something happened.

Many sentences also have an object: the person or thing affected by the action.

Nadia sent an email.
Nadia called her manager.

Consider this statement:

Peter called me yesterday.

There are two possible questions with who, but they ask for different missing information.

What you do not know	Question	Answer
the person who made the call	Who called you yesterday?	Peter.
the person Peter called	Who did Peter call yesterday?	You.

The first question asks about the subject. Who replaces Peter, the person doing the action.

The second asks about the object. Who replaces me, the person receiving the action.

A helpful habit is to imagine the full answer sentence first. Ask yourself:

• Is the unknown person or thing doing the action? Use a subject question.
• Is the unknown information a person, thing, place, time, or reason connected to the action? Use the usual object-question pattern.

Strictly speaking, where, when, and why often ask about details rather than an object. However, they use the same word order as object questions, so it is useful to learn them together.

---

Object questions: use the auxiliary

For most present and past simple questions, English needs an auxiliary verb:

Tense	Pattern	Example
Present simple	question word + do/does + subject + base verb	Where do they work?
Present simple	question word + does + he/she/it + base verb	What does she need?
Past simple	question word + did + subject + base verb	When did you arrive?

The main verb must be in its base form after do, does, or did.

Correct: Where does your brother work?
Incorrect: Where does your brother works?

Correct: What did they buy?
Incorrect: What did they bought?

This is because does already carries the present-tense ending, and did already carries the past meaning. The main verb does not repeat that grammar.

Here are common questions you can use in conversation:

What do you usually do after work?
Where does your colleague live?
Why do they need the information?
Who does she speak to at work?
When did you start this course?
What did you do last weekend?
Where did he put the document?
Why did the meeting finish early?

Notice that who does not automatically make a question a subject question:

Who did you speak to?
This is an object question because you are the subject and who is the person you spoke to.

In everyday English, it is natural to leave the preposition at the end:

Who did you speak to?
What are you waiting for?

Do not remove the preposition if it is needed for the meaning.

Questions with be

When the main verb is be, do not use do, does, or did. Put be before the subject.

Tense	Pattern	Example
Present simple	question word + am/is/are + subject	Where are you?
Past simple	question word + was/were + subject	Why was he late?
Present continuous	question word + am/is/are + subject + verb-ing	What are they doing?
Past continuous	question word + was/were + subject + verb-ing	Where were you going?

Compare:

What does she do?
This asks about her job or usual activity.

What is she doing?
This asks about her activity now.

The difference is not only vocabulary. It is a different tense and a different question structure.

The following short video gives a clear visual explanation of object-question structure in the present and past, then contrasts it with subject questions.

---

Subject questions: no do, does, or did

A subject question asks: Who or what did the action?

Start with who or what, then use the verb in the normal statement form. There is no extra subject because the question word itself is the subject.

Someone works here.
Who works here?

Someone broke the glass.
Who broke the glass?

Something happened.
What happened?

For common simple tenses, the patterns are:

Tense	Pattern	Example
Present simple	who/what + verb	Who lives next door?
Past simple	who/what + past verb	Who called this morning?

In present simple subject questions with who or what, use the usual third-person singular verb form:

Who needs help?
Who knows the answer?
What causes this problem?

Even if several people may be the answer, the standard question remains singular:

Who lives in that apartment?
My parents live there.

Do not add does:

Correct: Who uses this computer?
Incorrect: Who does use this computer?

There is one exception in meaning, not in basic grammar: speakers can use does for strong emphasis, such as “So who does live there?” For normal everyday questions, use the simpler form: “Who lives there?”

Subject questions can also use be when the tense requires it:

Who is calling?
Who is sitting near the window?
Who was working when you arrived?
What was happening at 9 p.m.?

Here, who is still the subject. The verb phrase needs is or was because it is continuous, but there is no inversion with another stated subject.

---

One pair, two meanings

The most reliable way to learn this distinction is to compare pairs that use the same words.

Statement	Subject question	Object question
Maria helps Daniel.	Who helps Daniel?	Who does Maria help?
The manager sent the link.	Who sent the link?	What did the manager send?
Someone took my phone.	Who took your phone?	What did someone take?
A customer is waiting outside.	Who is waiting outside?	Where is the customer waiting?
Someone was using the printer.	Who was using the printer?	What was someone using?

Look closely at the simple past pair:

Who sent the link?
Subject question: the unknown person performed the action.

What did the manager send?
Object question: the manager is known; the unknown item received the action.

The word order tells the listener what information you are asking for.

A common mistake is to use object-question word order when you need a subject question:

Incorrect: Who did send the link?
Normal question: Who sent the link?

Another common mistake is the opposite:

Incorrect: Who Maria called?
Correct: Who did Maria call?

---

A quick decision method

When you want to form a question, begin with the answer sentence, even if you only say it silently.

For example:

Ahmed repaired the laptop yesterday.

1. If the missing answer is Ahmed, ask a subject question:
   Who repaired the laptop yesterday?

2. If the missing answer is the laptop, ask an object question:
   What did Ahmed repair yesterday?

3. If the missing answer is yesterday, use the object-question pattern:
   When did Ahmed repair the laptop?

4. If the action is happening now, keep the necessary form of be:
   What is Ahmed repairing?
   Who is repairing the laptop?

This method is especially useful in online meetings and everyday conversations. You may hear an incomplete piece of information and need to ask quickly:

“Someone changed the meeting time.”
Who changed it?
When did they change it?
What time did they choose?

The first question asks for the person responsible. The next two ask for details, so they use did + subject + base verb.

For a short speaking check, take three recent events from your life—for example, a message, a purchase, or a meeting. For each event, say one subject question and one object question aloud. Reconstruct the answer sentence after each question; it will show you whether your word order is accurate.

Cambridge Grammar presents the same central contrast: ordinary information questions generally use an auxiliary, while who or what as the subject does not use do, does, or did.

---

Key takeaways

Subject and object questions often look similar, but they ask for different missing parts of a sentence.

• A subject question asks who or what performs an action: “Who called?” or “What happened?”
• In present and past simple subject questions, do not use do, does, or did: “Who works here?” and “Who arrived late?”
• An object question asks about the object or another detail: “Who did you call?”, “What did you buy?”, and “Where does she work?”
• With do, does, or did, use the base verb: “What did he say?”, not “What did he said?”
• With the verb be, use am/is/are or was/were directly: “Where are you?” and “Why was she late?”
• When unsure, rebuild the answer as a statement. If the unknown information is the doer, form a subject question; otherwise, use the object-question pattern.

Next, you will practise time markers such as since, for, already, yet, and ago, choosing the tense that naturally fits each one.