Could I go out for dinner with my friends?Sure, that should be OK.Could we get something to drink after the movie?No, you can’t. You have a basketball game tomorrow.Could you please take the dog for a walk?OK, but I want to watch one show first.Could you please take out the rubbish?Yes, sure.阅读下列句子，观察问句的用法及回答。Key sentence structures Could you （ please ） + V- 原形？表示委婉地提出请求1. Could you please clean your room? Yes, sure./ Of course./ Certainly./All right.2. Could you please do the dishes? Sorry, I can’t. I have to do my homework. —Peter, could you please take out the trash? —Sure, Mom. —Could you please do the dishes? —Sorry, I can’t. I have to do my homework. 在表示请求帮助或请求允许的疑问句中，常用 could 代替 can ，以表示礼貌，委婉或不确定的语气，而 can 则不具备这些语气。这种情况下不能把 could 看作 can 的过去式。以上两句中用 could 是为了表示礼貌的请求。表示请求帮助或请求允许时，除了 can, could 之外，还可以用 may ，句子的表达方式也各有不同，可以用不同的方式来表示同一个概念。例： ① Could/Can/May I use your car for a day? ② I wonder if I could use your car for a day? 对于①、②句所作允答可以各种各样，如同意可以说 Yes 或 Sure 或 Certainly ，还可说 Yes, (do) please. 或 Of course. (you may/can). 或 Go ahead, please. 或 That’s OK/all right; 如果不同意，可以说 I’m sorry you can’t. 或 I’m really sorry, but I have to use it today. 要避免说 No, you can’t. 这样显得很不礼貌。否定回答通常用委婉语气。 ③ Do you mind if I use your car for a day? 对于句③所作回答可以说 Never mind. /Not at all. 表“不介意”。不能用 Yes. /Sure. /Of course. /Certainly. 等。无论肯定还是否定应答中，要避免使用 could ，要用 can 或 may 。因为应答须用确定的语气。而 could 在表请求的问句中是为了表示礼貌或委婉语气，用在应答中则成了不确定语...
