Was my answer correct?

If not please explain why as I‘d like to learn/understand. My understanding is that you can form a statement into a question just with a question mark, and my answer is a correct statement, so why can’t it be a question also?

Thanks in advance

If not please explain why as I‘d like to learn/understand. My understanding is that you can form a statement into a question just with a question mark, and my answer is a correct statement, so why can’t it be a question also?

Thanks in advance