情态动词专题.ppt

情态动词 一、用法 从高考及平时各类考试情态动词的推测用法来看，主要有must, should, can (could), may(might)几个词，现对它们的用法按可能性从大到小排列列表如下： mustshould cancouldmay might 一、用法 一般式：must/ should/ can/ could/ may/ might do sth. 进行式： must/ should/ can/ could/ may/ might be doing sth. 完成式： must/ should/ can/ could/ may/ might have done sth. 例题 1．表推测时，might不是may的过去式，could不是can的过去时，而是表示might/ could的可能性比may/ can还小，所以，上述情态动词的过去式并不表示对过去的情况进行推测。 2．should表示根据事物内在发展的规律、事情发展的必然性得出的结论，表示“某人（某事）按道理应该（理应）……”。 3．can/ could常用于否定句和疑问句中表示推测，但在表示“有时候可能”或“从理论上讲”时，也可用于肯定句中。 4．may/ might not用于否定句中表“可能不”，而不是“不可能”。 1. He ______ have completed his work; otherwise, he wouldn’t be enjoying himself by the seaside. (2009北京卷) A. should B. must C. wouldn’t D. can’t 2. This cake is very sweet. You ______ a lot of sugar in it.（2005辽宁卷） A. should put B. could have put C. might put D. must have put 3. —Is John coming by train? —He should, but he ______ not. He likes driving his car. (NMET2002) A. must B. can C. need D. may 4. My English-Chinese dictionary has disappeared. Who ______ have taken it?（2010上海春季） A. should B. must C. could D. would 5. —When can I come for the photos? I need them tomorrow afternoon. —They ______ be ready by 12:00.（NMET1998） A. can B. should C. might D. need 6. —Isn’t that Ann’s husband over there? —No, it ______ be him—I’m sure he doesn’t wear glasses.（NMET2004） A. can’t B. must not C. won’t D. may not 7. —Excuse me. Is this the right way to the Summer Palace? —Sorry, I am not sure. But it ______ be.（2009湖北） A. might B. will C. must D. can 8. My sister met him at the Grand Theatre yesterday afternoon, so he ______ your lecture.（2008上海） A. couldn’t have attended B. needn’t have attended C. mustn’t have attended D. shouldn’t have attended 9. Sorry, I’m late. I ______ have turned off the alarm clock and gone back to sleep again.（2008北京春季） A. should B. can C. might D. will 10. It’s nearl