Indirect questions

An indirect question is a question inside another sentence (Do you know…?, Could you tell me…?, I wonder…). The question inside uses statement word order: question word + subject + verb, and do / does / did disappear.

💡When does / did disappear, their tense moves to the main verb: What time does it open? → … what time it opens. Why did she leave? → … why she left.

1. Asking politely, especially strangers, customers or your boss — softer than a direct question

• Excuse me, do you know where the nearest ATM is?

• Could you tell me how far it is to the airport?

• Would you mind telling me what you think of the plan?

2. Saying what you are wondering about or don't know — these are statements, so they end with a full stop

• I wonder what she wants for her birthday.

• I have no idea where he went last night.

• I can't remember where I parked the car.

• Openers that are questions (?): Do you know…? / Could you tell me…? / Can you tell me…? / Do you have any idea…? / Would you mind telling me…? / Can you remember…?
• Openers that are statements (.): I wonder… / I don't know… / I'm not sure… / I have no idea… / I'd like to know… / I can't remember…
• The final punctuation follows the outside sentence, not the question inside.

A yes/no question has no question word, so add if or whether. They mean the same; whether is a little more formal and often goes with or not.

• Do you know if the restaurant is open today?

• I'm not sure whether it will rain or not.

• It depends on whether we have enough time.

  after a preposition, only whether

• I can't decide whether to buy it.

  before to + verb, only whether

If who / what / which is the subject, the direct question already has statement word order (no do/did), so nothing changes in the indirect question. See also the lesson “Subject and object questions”.

• Who broke the window? → Do you know who broke the window?

• What happened? → Can you tell me what happened?

But with be + noun, be moves to the end: Who is that man? → Do you know who that man is? (not: who is that man).

💡Indirect questions don't move the tense back, because you are asking now: Do you know where she lives? You only move it back when reporting someone else's question: She asked me where I lived — see the lesson “Reported speech”.

• ✗Do you know where is the post office?

  ✓Do you know where the post office is?

  The question inside uses statement order: subject + verb.

• ✗I wonder what does she want for her birthday.

  ✓I wonder what she wants for her birthday.

  Drop does and add -s to the main verb.

• ✗Can you tell me does this bus go to Ben Thanh Market?

  ✓Can you tell me if this bus goes to Ben Thanh Market?

  Yes/no question → if/whether + statement.

• ✗Do you know how old is your grandfather?

  ✓Do you know how old your grandfather is?

  How old + subject + be.

• ✗Could you tell me where did you buy that jacket?

  ✓Could you tell me where you bought that jacket?

  Drop did and put the main verb in the past.

• ✗I don't know where she's going?

  ✓I don't know where she's going.

  The outside sentence is a statement, so it ends with a full stop.