四级语法讲座6：情态动词.ppt

重点九 情态动词 i. 考点分析 l 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： l1. 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cant或couldnt。 l must + have +done ：表示对过去情况的一种肯定的推测与 判断 l 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。 l 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。 l 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。 l neednt + have + done：表示本不必做的事却做了。 l2. 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。 l you oughtnt to be talking so much. l he cant be swimming all day. l3. 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 。 l you must have been overdoing things a bit. l you should have been waiting for us. i. 考点分析 情态动词 自 测 l l1) 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 l3)it was very kind of you to do the washing- up,but you_ it.(1998.6) a. mustnt have done b. wouldnt have done c. mightnt have done d. didnt have to do 4) if you dont like to swim, you _ stay at ho me.(1995.1) a. should as well b. may as well c. can as well d. would as well d b l5) you _ him so closely;you should have kep t your distance.(2000.6) a. shouldnt follow lb. mustnt follow lc. couldnt have been following ld. shouldnt have been following 6) you _her in her office last friday; shes be en out of town for two weeks.(19996.1) a. neednt have seen b. must have seen c. might have seen d. cant have seen d c 7) the room is in a terrible mess; it _ cleaned.(1996.6) a. cant have been b. shouldnt have been c. mustnt have been d. wouldnt have been a 3 情态动词的应对策略 l 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。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? l2）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cant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, cant用而不是may, may not。如： he cant have stolen the money; he is not such kind of p erson. some pleasant thing must have happened to him. he is so excited. 3 情态动词的应对策略 l3） 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 l4） 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： lcould have done本来能够 he didnt take part in the competition, he _ though. a. won b. didnt win c. could win d. could have won lneednt have done 本来没不要 you _. there was plenty of time. a. neednt hurry b. cant hurry c. mustnt have hurried d. neednt have hurried lshould/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. neednt have told 3 情态动词的应对策略 lshouldnt/oughtnt to have done 本来不应该 you _ him so closely; you should have kept your dis tance. a. shouldnt follow b. mustnt follow (2000.6) c. couldnt have been following d. shouldnt have been following lmight 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 l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 l5） 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 l1. i wish i _ longer this morning , but i had to get up and come to class. (95/6/45) l a) could have slept b) slept l c) might have slept d) have slept la) 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。 l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)。 l2. this box is too heavy, _ give me a hand？ (98/1/34) l a) would you mind b) would you please l c) will you like to d) will you please to lb) 题意：这个箱子太重了，请你帮我一下好吗？ l解析：表示礼貌地请求，只能用b。would you mind 后加动名词。 l3. research findings show we spend about two hours dreaming every night, no matter what we _ during the day. (99/1/54) l a) should have done b) would have done l c) may have done d) must have done lc) 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。 l解析：表示可能已经做，只能用c)。 l4. we have been told that under no circumstances _ the telephone in th le office for personal affairs. (99/6/60) la) did we use b) may we use lc) we may use d) we could use lb) 题意：我们被告知无论在什么情况下都不能因私事 而用办公室的电话。 l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)。 l5. some women _ a good salary in a job instead of staying home, but they decided not to work for the sake of the family. (00/1/70) l a) would make b) must make l c) could have made d) should have made lc) 题意：有些妇女如果不待在家里本可以找到一份高 薪的工作，但是她们决心为了家庭而不解析：去工作 。could have done 表示本可以作却没有作。 l6. if you dont like to swim, you _ stay at home. (95/1/60) la) should as well b) may a