英语人教版八年级下册情态动词could的用法ppt课件.ppt

Grammar Focus,情态动词could,If we need help, what should we say politely?,Which is the most polite one?,1. Sweep the floor, Peter!,2. Can you sweep the floor, Peter?,3. Could you please sweep the floor，Peter?,Could you please clean your room? Yes, sure.Could you please do the dishes? Sorry, I cant. I have to do my homework.Could I go to the movies? Yes, you can.Could I use the car? No, you cant. I have to go out.,1. could表示请求，语气委婉，显得有礼貌 Could you please clean your room? 你可以打扫你的房间吗？ 肯定回答：Yes, I can. Yes, sure. / Yes, of course. 是的，我可以。 否定回答： Sorry, I cant. I have to do my homework. 对不起，我不得不做作业。,2. could表示请求许可，希望得到允许。 Could I go to the movies? 我能去看电影吗？ 肯定回答：Yes, you can. Yes, sure. 当然可以。 否定回答：No, you cant. 不，不行。,在表示请求帮助或请求允许的疑问句中，我们常用could代替can， 以表示礼貌、委婉或不确定的语气，而can 则不具有这些语气。这样用时，不能把could 看作为can 的过去式形式。,3. could与can的区别 could与can都是情态动词，could是can的过去式。二者都可用于表示请求，但是用法稍有不同。 can表示一般性的请求，语气随便，常用于熟人之间或长辈对晚辈、上级对下级的场合； Can you tell us your story, Tony ? 你能给我们讲讲你的故事吗，Tony？,could表示有礼貌的请求，语气委婉，常用于非熟人之间或晚辈对长辈、下级对上级的场合。 Could you tell us if it snows in winter in Australia? 请告诉我们，澳大利亚冬天下雪吗？Sure. 当然可以。, Could you please do sth?,Could you please ?,sweep the floor,fold your clothes,cook the meal,clean the window,小试牛刀( )1. Excuse me, could you help me with the heavy box? _. A. Yes, I do B. It doesnt matter C. Of course,小试牛刀( )2. Could I have your name, please? _. A. Sorry, Im not B. Yes, you could C. You can call me Jenny,小试牛刀( ) 3. Could you please _ me look for my dog? A. help B. helped C. to help( )4. Could I use your bike? Sure, you _. A. might B. can C. should,Could的用法,1.I could run fast when I was a child.,2.Could you help me?,3.You could talk to your teacher now.,4.He couldnt be at the school then.,can 的过去式,礼貌的请求,提出建议,推测,HomeworkCould you please write down 5 sentences how to ask or suggest?,