1 、 Could I borrow your book? Yes. Of course you can. 2. Would you like to do it for me ? Yes. I would. 一、情态动词注意事项
(1) 对现在或将来情况推测： must + 动词原形。 must 只能用于肯定。否定和疑问分别用 can’t 和 can 。 He must tell a lie. Can he tell a lie ? He can’t tell a lie. *Must-should/ought to –may-might/could+do 可能性依次减弱 2 、推测语气
(2) 对过去情况推测： must (may, might)+ 完成时。 You must have met him before. must—may—might 可能性依次减弱 must 只能用于肯定句，译成 “ 一定 ” 。否定 和疑问分别用 can’t / couldn’t 和 can / could 。 Could /Can it have happened last night ? It couldn’t/can’t have happened last night.
He must be reading, isn’t he? You must do it yourself, don’t you? He must have gone over the article, hasn’t he? It must have rained last night, didn’t it? 3 、表猜测语气的反意疑问句的构成
would need used to do dare mustn’t don’t have to=needn’t may/might do/have done 不妨 …; 还是 … 为好 4 、 be able to must can have to
1 ）用于第一人称表将来。 I shall go to work after I have finished school. 2 ）用于一、三人称疑问句、表征求对 方意见或向对方请求。 Shall he come in? — Come in, please. 3 ）用于二、三人称，表示保证、承诺、 威胁、警告。 You shall be punished if you insist on doing it this way. 5 、 Shall
1 ）预测、可能。 They should be here by now. 2 ）说话人的感情。如惊奇、愤怒、 失望等、 “ 竟然 ” You can’t imagine that well-behaved gentleman should be so rude to a lady. 6 、 should
1 ）对过去情况推测。 must/may/might have done can’t/couldn’t/may not/might not have done can/could have done…? 7 、情态动词 +have done
2 ）译成 “ 本 …”could/should/need have done. You should have come here five minutes earlier. 3 ）虚拟语气（与过去事实相反的主句） If you had followed my advice, you wouldn’t have been defeated.