Forming questions

If there is an auxiliary (helping) verb (be, have, can, will, etc.) we put it before the subject (he, she, I, etc.)

Is anybody in the office?
Have you ever visited London?
What time Will they be here?

If there is no auxiliary (helping) verb, we put do, does or did before the subject.

Do you know my older brother?
Did he come in time?

We put wh- words (when, where, why, who, how, etc.) at the beginning of the question.

How long have you been waiting for me?
Where is their office?
Which colour do you like best?

We don't use do, does or did when we use what, which, who or whose as the subject.

What happened to you?
Who told you about it?

What did you mean by saying that?

If there is no auxiliary (helping) verb, we put do, does or did before the subject.

Do you like this film?

Where are you going this afternoon?

We put an auxiliary verb before the subject.

Did you read the letter?

Who gave you the information?

We don't use do, does or did when we use what, which, who or whose as the subject.

Does he know your sister?

When there is an auxiliary verb, the main verb is in the infinitive form.

Where will she study?

Can you tell me where I can buy a good camera?

Word order in indirect question is the same as in a normal sentence: SUBJECT + VERB + ...