Indirect questions

Form:  introductory phrase or question + clause with normal word order
Use:  We use i ndirect questions when we want to ask questions politely.

• We do not use question word order in the second part of the sentence.
✓ I would like to know when the next train to London leaves.
✘ I would like to know when does the next train to London leave.

• Some indirect questions, which begin with a question word, need a question mark at the end.
✓ Could you tell me where the library is?

• If a direct question is a 'yes/no' question, the equivalent indirect question uses if or whether.
✓ I wonder if/whether you have read this book.