A.
When we ask for information, we often say Do you know…?/Could you tell me…? etc. If you begin a question like this, the word order is different from a simple question.
Compare:
Where has Tom gone? (simple question)
but Do you know where Tom has gone? (not ‘Do you know where has Tom gone?’)
When the question (Where has Tom gone?) is part of a longer sentence (Do you know…?/I don’t know…/Can you tell me…? etc.), it loses the normal question word order.
Compare:
* What time is it? but Do you know what time it is?
* Who is that woman? but I don’t know who that woman is.
* Where can I find Linda? but Can you tell me where I can find Linda?
* How much will it cost? but Have you any idea how much it will cost?
Be careful with do/does/did questions:
* What time the film begins? but Do you know what time the film begins? (not ‘Do you know what time does…’)
* What do you mean? but Please explain what you mean.
* Why did Ann leave early? but I wonder why Ann left early.
Use if or whether where there is no other question word (what, why etc.):
* Did anybody see you? but Do you know if (or whether) anybody saw you?
B.
The same changes in word order happen in reported questions:
direct: The police officer said to us, “Where are you going?
reported: The police officer asked us where we were-going.
direct: Clare said, ‘What time do the bank close?
reported: Clare wanted to know what time the banks closed.
In reported questions, the verb usually changes to the past (were, closed). See Unit 46.
Study these examples. You had an interview for a job and these were some of the questions the interviewer asked you:
INTERVIEWER
How old are you?
What do you do in your spare time?
How long have you been working in your present job?
Why did you apply for the job?
Can you speak any foreign languages?
Have you got a driving licence?
Later you tell a friend what the interviewer asked you. You use reported speech:
* She asked (me) how old I was.
* She wanted to know what I did in my spare time.
* She asked (me) how long I had been working in my present job.
* She asked (me) why I had applied for the job. (or… why I applied)
* She wanted to know whether (or if) I could speak any foreign languages.
* She asked whether (or if) I had a driving licence. (or… I had got… )