四级语法讲座6：情态动词.ppt

四级英语 语法讲座,,,,重点九 情态动词,I. 考点分析,情态动词是一项非常重要的语法考点在考试中大多与虚拟语气放在一起，有时也会单独出现，请特别注意以下几点： 1. 用于表示判断的情态动词表示肯定判断的有must, may/might，表示否定判断的用can’t或couldn’t must + have +done ：表示对过去情况的一种肯定的推测与判断 may(might) + have + done：表示对已发生的事情的不太肯定的推测might比may语气弱，表示把握更小 should(ought to)+ have + done：肯定句表示过去本应发生的事却没有发生；否定句表示不该发生的事却发生了 could + have + done：有时表示过去的时间，说明某事可能已发生，有时也表示过去本来可以作的事却未作 needn’t + have + done：表示本不必做的事却做了2. 情态动词也可以和动词的进行形式构成谓语，表示应当正在作某事，或想必正在作某事或既将、将要做某事 You oughtn’t to be talking so much. He can’t be swimming all day. 3. 情态动词也可和动词的完成进行式构成谓语，表示应当一直在做某事或想必一直在做某事。

You must have been overdoing things a bit. You should have been waiting for us.,I. 考点分析,情态动词 自 测,,1) This box is too heavy, _________give me a hand?(1998.1) A .would you mind B. would you please C. will you like to D. will you please to 2) Research findings show we spend about two hours dreaming every night , no matter what we ____ during the day.(1999.1) A. should have done B. would have done C. may have done D. must have done,B,C,3)It was very kind of you to do the washing-up,but you____ it.(1998.6) A. mustn’t have done B. wouldn’t have done C. mightn’t have done D. didn’t have to do 4) If you don’t like to swim, you ___ stay at home.(1995.1) A. should as well B. may as well C. can as well D. would as well,D,B,5) You ____ him so closely;you should have kept your distance.(2000.6) A. shouldn’t follow B. mustn’t follow C. couldn’t have been following D. shouldn’t have been following 6) You ___her in her office last Friday; she’s been out of town for two weeks.(19996.1) A. needn’t have seen B. must have seen C. might have seen D. can’t have seen,D,C,7) The room is in a terrible mess; it ____ cleaned.(1996.6) A. can’t have been B. shouldn’t have been C. mustn’t have been D. wouldn’t have been,A,3． 情态动词的应对策略,情态动词的使用主要根据其所表达的含义。

解题时注意以下几点： 1）情态动词自身结构要正确 结构包括情态动词自身的搭配和其后的连带成分除ought外情态动词后接原形动词，测试中常将不同结构的动词置于一起设干扰项，如①四个选项都与请求有关，但would you mind后接动名词，一般说would you like to而不是will you like to，will you please后用原形动词，答案是would you please?,2）注意情态动词推测性用法中各个情态动词使用的句型是否与题干句型一致 在情态动词的推测性用法中，must, can, may, might, could各用于不同的句型，应注意分辨具体使用规律为： must只用于肯定句中 can/could不能用于肯定句中 may/might不能用语疑问句中 另外还应注意can’t表示“不可能“，may not表示“可能不“ 考试时，如果有原因说明自己的猜测，一般应该must, can’t用而不是may, may not如： He can’t have stolen the money; he is not such kind of person. Some pleasant thing must have happened to him. He is so excited.,3． 情态动词的应对策略,3） 注意推测性用法中谓语动词发生的时间。

如果推测的为过去的事情，情态动词后则用完成形式 There must have been no one in, for nobody answered the phone. 如果推测的是正在进行的事情，情态动词后则用动词的进行形式 They must be talking about something very secret. 如果推测的是现在的状态等，情态动词后则用原形动词 He must be badly ill. He looks so pale. 如果推测的是将来发生的事情，情态动词后同样用原形动词，这时，情态动词只能是may/might There may be a terrible storm in the following few days.,3． 情态动词的应对策略,4） 注意“情态动词+动词的完成形式”所表达的意思与题干意思是否相符 其它“情态动词+ 动词的完成形式”并不表示推测，而分别表示： could have done本来能够 He didn’t take part in the competition, he _______ though. A. won B. didn’t win C. could win D. could have won needn’t have done 本来没不要 You ________. There was plenty of time. A. needn’t hurry B. can’t hurry C. mustn’t have hurried D. needn’t have hurried should/ought to have done 本来应该 You _______ me earlier. I could have helped you. A. should tell me B. should have told C. need to tell D. needn’t have told,3． 情态动词的应对策略,shouldn’t/oughtn’t to have done 本来不应该 You ____ him so closely; you should have kept your distance. A. shouldn’t follow B. mustn’t follow (2000.6) C. couldn’t have been following D. shouldn’t have been following might have done 本来应该（用来表示一种责备） You ______ even though you were busy at that time. A. might help him B. must have helped him C. might have helped him D. should help him 这类题在设计干扰项时，一般都会有情态动词推测性用法的涉及，应注意分词上下文的逻辑和语意关系。

3． 情态动词的应对策略,5） 注意常用情态动词的基本句法和表意功能 其它常用动词的用法，如shall表示“命令”、“威胁”、“许诺”或征求许可，may/might as well等， 应多多注意其用法3． 情态动词的应对策略,四级真题 情态动词,1. I wish I _____ longer this morning , but I had to get up and come to class. (95/6/45) A) could have slept B) slept C) might have slept D) have slept A) 题意：我真希望今天早上能多睡一会，但我不得不起床去上课 解析：wish后接从句，表达不可能实现或与事实相反的情况时，谓语动词要用虚拟语气用过去式，表示现在发生的动作；用过去完成式，表示过去发生的动作因此选A) 2. This box is too heavy, _____ give me a hand？(98/1/34) A) would you mind B) would you please C) will you like to D) will you please to B) 题意：这个箱子太重了，请你帮我一下好吗？ 解析：表示礼貌地请求，只能用[B]。

would you mind 后加动名词3. Research findings show we spend about two hours dreaming every night, no matter what we _____ during the day. (99/1/54) A) should have done B) would have done C) may have done D) must have done C) 题意：调查结果表明，无论我们白天做了什么，我们每晚都会作两小时的梦 解析：表示可能已经做，只能用C) 4. We have been told that under no circumstances _____ the telephone in th e office for personal affairs. (99/6/60) A) did we use B) may we use C) we may use D) we could use B) 题意：我们被告知无论在什么情况下都不能因私事而用办公室的 解析：under no circumstances 决定了后面的句子应主谓倒装。

由主句时态和句意理解，应选B)5. Some women _____ a good salary in a job instead of stayin。