Timothy. Thank you.

Also, when you have a question word in the sentence, you do not add "吗“ 그리고 장문 안 에 의문 단아 있으면 (예:什么，谁，哪里... 기타) ”吗“를 빼세요.

俞亭， 谢谢你

不是。when you bought something, and you don't sure that how much change you should take, you ask "你要找我多少钱" maybe similar to "How much change should I take?"

How much money do you want to borrow me? 对吗