1情态动词和虚拟语气情态动词考点一：情态动词的基本用法1.can/could 的基本用法(1)表示能力。(2)表示请求和允许，表示请求时，口语中常用 could 代替 can。(3)表示惊讶、怀疑和不相信，主要用于否定句、疑问句和感叹句。The police still havent found the lost child, but theyre doing all they. (2011四川高考)AcanBmay Cmust Dshould2may/might 表示允许、许可，在表示请求、允许时，might 比 may 的语气更委婉。 I take the book out ？ Im afraid not. (2010四川高考)AWill BMay CMust DNeed3must(1)表示必须、应该，其否定词 mustnt 表示“ 不准；不许可；禁止”之意。(2)对以 must 开头的疑问句作否定回答时，要用 neednt 或 dont/doesnt have to。(3)have to 和 must 意 思 相 近 ， 只 是 must 侧 重 表 示 说 话 人 的 主 观 看 法 ， 而have to 则 表 示 客 观 需 要 。 Shall I inform him of the change of the schedule right now？ I am afraid you ， in case he comes late for the meeting. (2011福建高考)Awill Bmust Cmay Dcan4shall (1)用于第一、三人称的疑问句中，表示征求对方的意见。(2)用于第二、三人称的陈述句，表示说话人给对方的命令、警告、允诺、威胁；此外当颁布法律规定时，也用 shall。 Will you read me a story, Mummy？ OK. You have one if you go to bed as soon as possible. (2011陕西高考)Amight Bmust Ccould Dshall 5will/would (1)用于表示意志和意愿。( 2)表 示 “请 求 和 建 议 ”， 用 would 比 will 更 委 婉 、 客 气 些 。(3)表示习惯，will 可以表示现在的习惯，常译为“总是”，表示过去的习惯性动作用would。(4)表示事物的某种性质和倾向。 Why didnt you come to Simons party last night？ I wanted to, but my mom simply not let me out so late at night. (2011重庆高考)Acould Bmight Cwould Dshould考点二：情态动词表推测，可能性1.can (1)表示理论上的可能性， “有时候可能会”。即使一位有经验的老师也可能犯错误。_ (2)表示推测，译为“可能”，用于否定句和疑问句。他不可能来。雨下得这么大。_It be the postman at the door. Its only six oclock. (2011江西高考)Amustnt Bcant Cwont Dneednt2may 表示可能性的推测，含有“也许、可能”之意，用 might 代替 may 时，语气显得更加不肯定。用于肯定句和否定句。他们可能现在在教室里。_ I dont really like James. Why did you invite him？2 Dont worry. He come. He said he wasnt cer tain what his plans were. (2011北京高考)Amust not Bneed not Cwould not Dmight not3. must 表示有把握的推测，只用于肯定句。他一定在宿舍里睡觉呢。_ Good morning. Ive got an appointment with Miss Smith in the Personnel Department. Ah, good morning. You be Mrs. Peters. (2010北京高考)Amight Bmust Cwould Dcan4should 用来表示推测时意为 “应该”，即含有“按道理来说应当如此”的意思。What do you mean，there are only ten tickets？There be twelve.(2009全国卷)Ashould Bwould Cwill Dshall考点三：情态动词的特殊用法1.“cannot (help/choose) but动词原形 ”表示“不得不；只好”我只好去。_2cannot/can never .enough/too .表示“再也不为过”过马路时你怎么小心都不为过。_3may 可以用于祈使句中表示祝愿愿我们彼此永不忘。_4may as well 表示“最好；倒不如”你最好马上就做这件事。_5must 表示“偏偏；硬要”If you go, at least wait until the storm is over. (2011辽宁高考)Acan Bmay Cmust Dwill考点四：“情态动词+ have done” 表示推测，必要性情态动词have过去分词 用法must have done 表示对过去已经发生的行为进行推测，意为“想必/准是/一定做了某事”can/could have done 表示对过去发生的行为的怀疑和不肯定，通常用在否定句和疑问句中could have done 可用于肯定句中，表示“可能已经” ；此外，还可表示过去没有实现的可能性，意为“本来可以”情态动词have过去分词 用法may/might (not) have done表示对过去已发生行为的推测，用于肯定句中，表示“也许已经” ；在否定句中表示“可能不” ，用 might 则表示语气更加不肯定should/ought (not) to have done用于肯定句中，表示“本该做某事，而实际上未做” ；用于否定句中，则表示“不该做的事反而做了”neednt have done 表示“本来没必要做某事” ，指做了本来不必去做的事They must have fallen asleep. _I saw Mr. Wang just now. He couldnt have gone to Beijing._3You could have done better, but you were too careless._You should have come to the meeting earlier. _You neednt have taken a taxi, for it was very near _ I left my handbag on the train，but luckily someone gave it to a railway official. How unbelievable to get it back！ I mean, someone it. (2011江苏高考)Awill have stolen Bmight have stolen Cshould have stolen Dmust have stolenThey have arrived at lunchtime but their flight was delayed. (2011全国卷)Awill Bcan Cmust Dshould虚拟语气考点一：虚拟语气在条件状语从句中的运用虚拟条件句 主句 例句与现在事实相反的假设If主语动词的过去式(be 动词通常用 were)主语should/would/could/might动词原形If we had time now, we would read it again.与过去事实相反的假设If主语had 过去分词主语should/would/could/might have过去分词If I had taken his advice, I would not have made such a mistake.虚拟条件句 主句 例句与将来事实相反的假设If主语动词过去式If主语were to动词原形If主语should动词原形主语should/would/could/might动词原形If you came tomorrow, we would have the meeting.If it were to rain tomorrow，the sports meeting would be put off.If he should not come tomorrow，we should put off the meeting till next Monday. The weather has been very hot and dry. Yes. If it had rained even a drop, things would be much better now！ And my vegetables . (2010北京高考)Awouldnt die Bdidnt die Chadnt died Dwouldnt have died考点二：非真实条件句虚拟语气注意事项1.虚拟条件句的倒装如果虚拟条件句中含有 were，should，had 三个词(其中 should