精选优质文档-倾情为你奉上Unit3 Could you please clean your room?一 情态动词could 的用法1.提出礼貌的要求 Could you please (not) do sth ?请你（做）.好吗？用于提出请求，希望得到对方的肯定回答，说话的语气比较客气委婉。Could 不是can的过去式，是委婉、礼貌的说法。回答用can. 肯定回答：Yes,sure./ Yes, I can./Of course,I can./ Certainly./No problem./ With pleasure .否定回答： Sorry , I cant / Im afraid I cant. I have to ,Im going to(说明理由)2.表示请求许可 Could I do a sth? 我可以做.吗？肯定回答：Yes, you can ./ Yes ,please / Of course / Certainly./ No problem. 否定回答：Sorry , you
