Direct and indirect questions

Form and meaning

1. If we do not begin a question directly, but begin it with something like Can you tell me...? / Do you know...? / I wonder if...? the word order is the same as in an affirmative statement.
   • Direct question: What is he doing?
     Indirect question: Do you know what he is doing?
   • Direct question: Where have they been?
     Indirect question: I wonder where they have been?
2. If the direct question contains the auxiliary do, we omit it in the indirect question.
   • Direct question: What do you want?
     Indirect question: Can you tell me what you want?
   • Direct question: When did she leave?
     Indirect question: Do you know when she left?
3. In yes / no questions, we use if or whether. The word order is the same as in reported questions.
• Direct question: Have you seen my dog?
  Indirect question: Could you tell me if you have seen my dog?

Extracted from here

1. Exercises here
2. Listen to this explanation. You als have the transcript, a grammar explanation and exercises
3. Watch the flatmates episode on indirect questions and have a look at the grammar explanation and quiz.