1. Do you know what is this?
2. Do you know what this is?
Which is correct? why?
I think I should explain this question with a scenario, as in below.
Mary asks John: What is this?
As John does not know what is Tree, then he ask his friend Lucy: Do you know what is this?
Lucy says: I think it is a Car, you know what Car is, right?
John says: I don't know.
I think both 1 and 2 are correct.
Very clear, thanks.