摘要： 对重要的情态动词和虚拟语气的用法要做到重点掌握.多区分和体会. 例1. 26. What a pity. Considering his ability and experience, he better. A. need have done B. must have done C. can have done D. might have done [答案]D . [题源探究] 考查情态动词的完成形式的比较独特的用法用法. [广角思维] 该题提供的语境是他本可以做得更好的.但是却没能这样.Might have done 符合该语境. [易误警示] 有部分学生想到到了这一层意思“他本来能做得更好的 .这一意思是正确的.但是C项没有这一用法.选错答案的学生就范了这样的错误. [悟彻高考] (1) could后面接完成式 表示本可能发生或本可以做的事而没有发生或没有做,它的否定形式则表示本不可能发生或本不可以做的事而已经发生或已经做了.例如: The output could have been increased by 15% .产量本可以提高百分之十五的. How could he have forgotten him birthday ? 他怎么会忘了自己的生日呢? Judging from her appearance and manner, she couldn't have been over fifty years old . 从她的仪表和举止来看.她不可能已有五十多岁了. (2) ought to/should后面接完成式表示本应该发生或本应该做的事而没有发生或没有做,它的否定形式则表示本不应该发生或本不应该做的事而已经发生或已经做了.例如: They ought to have completed their work much earlier . 他们本应该在更早一些的时候完成他们的工作的. You oughtn't to have left your keys in the office when you went out . 你不该出去的时候将钥匙留在办公室里. I ought to have said it to her in a calmer mood . 我应该以更平静一些的语气对她说那件事的. (3)might后面接完成式 表示本可能发生或本可以做的事而没有发生或没有做.例如: They might have finished their work by now .他们现在或许已经完成任务. She might have done better than that .你本可以做得比这更好一些的. You might have learned more from him . 你本可以向他学到更多一些东西的. [同类预测] 上述三种结构并不是表示推测的.这一特征决定了该知识的重要性.使他们成为命题的重点和热点.: As it turned out to be a small house party, we so formally. A needn’t dress up B did not need have dressed up C did not need dress up D needn’t have dressed up 答案:D 解析: needn’t have + 过去分词.表示做了不必做的事.相当于 didn’t need to do ,译为“其实没必要-- .如: 例2:30.– I can’t find my purse anywhere. -- You have lost it while shopping. A. may B. can C. should D. would [答案]A. [题源探究] 该题考查情态动词的完成形式表示推测的用法. [广角思维] 根据语境可知是说“在购物的过程中可能把钱包丢失了. 符合这一语意的结构是may have done . [易误警示] 受can的汉语意思“可能 的影响很多学生会选择B.这是做该题时最容易犯的错误.忽略了can表示推测时用在问句中和否定句中这一用法特点. [悟彻高考] can, could后接完成式的用法:①在否定句或疑问句中表示对过去发生过的事情的“怀疑 或“不肯定 的态度.Could he have said so?. (2)may, might后接完成式的用法 ①表示对过去某事的推测.认为某一件事情在过去可能发生了.如果使用might.语气就比较婉转或更加不肯定.如:Mary might have learned some Chinese before. ②可以表示过去本来可以做到而实 际没有做到的事情.有“劝告 或“责备 的语气.如:You didn't do the work well that day. You might have done it better. (3)must后接完成式的用法:表示对过去某事的推测.认为某事在过去一定做到 了.如:Liu Dong isn’t in the classroom. He must have gone to the library. [同类预测]情态动词的完成形式表示推测的用法在各类命题中均很常见.它的重要性依然重要.依然会是命题考查的重点. My pain apparent the moment I walked into the room, for the first man I met asked sympathetically: Are you feeling all right? A must be B had been C must have been D had to be 答案:C 解析:must have+过去分词.表示对已发生情况的肯定推测.译为“一定--如: Mary my letter; otherwise she would have replied before A couldn’t have received B ought to have received C has received D shouldn’t have received 答案:A 解析:can’t / couldn’t have+过去分词.表示对已发生情况的否定推测.译为“一定没-- 例3:(2008年苏.锡.常.镇四市高三教学情况调查二) I ask him, because I think I be wrong. A. daren’t; must B. dare; must C. dare; mustn't D. daren’t; mustn't [答案]A. [题源探究] 本题主要考查dare的用法. [广角思维] 首先排除C/D. 根据语境可知是指不敢.答案A [易误警示] 分不清dare的词性.也因此无法断定选项中那一个是正确的. [悟彻高考] ①dare:作情态动词用.一般用于否定句.疑问句及条件状语从句中.一般不用于肯定句中.有时态变化.但没有人称变化.如: He dared not go out alone at night. 他夜晚不敢独自出去. I daren’t ask you, because I thought I was wrong. 我没敢告诉你.担心自己错了. ②dare:作行为动词用.在肯定句中常后接带to 的不定式,否定.疑问句中要用do, does, did等助动词.在否定和疑问句中可接带to或不带to的不定式.有人称和时态变化.如: I didn’t dare (to) come. 他不敢来. Does he dare (to) swim across the river? 他敢游过河吗? [同类预测]dare 的用法决定了其在高考中的地位和重要性.做该类试题时务必熟悉dare的词性.然后在根据所学的知识对对试题作出真确地判断. He his parents that he has failed in the exam. A. dares not tell B. dares not telling C. dare not tell D. dares not to tell 答案:C 解析:本题中dare是情态动词的用法. 巩固•应用测试

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