I know that "what is it that you want?" is grammatical. I made up the question "which tree is it that the Canadian flag shows a leaf of?" using my knowledge of English. I really need to know if it's correct, as it helps me to figure out how English works. Is it correct?
1 Answer
The form in your question is grammatical. (The form in the thread title isn't. It should not have the word the).
It's also a bit awkward. To ask for the same information, you could ask
What tree's leaf is on the Canadian flag?
or just
What kind of leaf is shown on the flag of Canada?