Why can't you say ...? Is this a mistake? What's wrong with (saying)...?
Why did you mark this wrong? Why did you put a line under this word?
Isn't there a mistake in sentence 3? Shouldn't there be an article?
I think you've made a mistake on the board.
How do you spell...? Are there two ‘l’s or only one?
How do you pronounce the next word? I'm not sure how to say the next word.
Could you use the future (passive) here? Can we leave this out (miss this out) ?
Is there a shorter (better) way of saying this?