Form and rules
How it works
1
After phrases such as Could you tell me..., Do you know..., I wonder..., use statement word order.
2
Keep a wh-word when the direct question has one: Where is it? → Do you know where it is?
3
For yes/no indirect questions, use if/whether: Do you know if the office is open?
4
Do not use do/does/did inside the embedded clause: Do you know where he works?
5
The outer question may take a question mark, while an embedded statement such as I wonder where he is does not need one.