考点识别：情态动词为必修三的语法点，从近几年的高考情况看，对情态动词的考查为高考重点项目之一，高考的热点依次为：推测和能力，必要性，请求建议命令，所以要求考生准确把握情态动词的意义和用法。
一、表推测词形肯定否定must 必然；一定—should 按说应该应该不会ought to 按说应该应该不会can/could 可能/微弱的可能不可能may/might 也许/微弱的可能可能不会技巧：做到情态动词表示推测的题，一定要把题目读完，根据题目所提供的信息判断填空部分所需要的语气。
e.g. He must be the wanted man, for he’s exactly like this picture.（因为他和照片很像，能够判断出语气是很肯定的）(2011 北京，24)—I don’t really like James. Why did you invite him?—Don’t worry. He come. He said he wasn’t certain what his plans were.A. must notB. need notC. would notD. might not二、表能力can:表示现在的能力could：表示过去的能力be able to will be able to: 将来的能力was/were able to：过去有能力并且成功地做了某事技巧：这三个词不易混淆，所以做此类题时，一般通过翻译就能选出答案。
但是要注意题目的时态。
e.g. (2010全国II, 17) I’m afraid Mr. Harding A see you now. He is busy.A. can’tB. mustn’tC. shouldn’tD. needn’t不能(2011 四川，20) The police still haven’t found the lost child, but they’re doing all they A .A. canB. mayC. mustD. should三、表必要性must: 一定，必须mustn’t: 不准，强行禁止have to: 不得不don’t have to: 不必need: 需要needn’t: 不需要e.g. (2011 上海，28) I D worry about my weekend—I always have my plans ready before it comes.A. can’tB. mustn’tC. daren’tD. needn’t不需要四、表请求、建议、命令、允许、禁止1.表示请求、建议：用于一、三人称，表示征求对方意见。
may/might：表示允许、请求。
will/would：用于第二人称，表示请求或建议。
e.g. Shall the driver wait outside?司机在外边等着可以吗？2.表示命令、允诺must 必须mustn’t 禁止；不准should/ought to 应该shouldn’t/oughtn’t to 不应该(易错点) shall:常与二、三人称连用，表命令、警告、威胁、允诺。
will:表示意愿、决心。
e.g.（2011 陕西卷）——Will you read me a story, Mummy?——OK. You _D_ have one if you go to bed as soon as possible.A. mightB. mustC. couldD. shall（允诺）情态动词+ have done一般考试时，常与虚拟语气连用来作为考点。
翻译该句型时，加个“本”字即可。
情态动词+ have done 用法例句must have done 一定/准是/想必做了It must have rained last night, forthe road is quite muddy.can/could have done 本来能够做Can he have gone to his aunt’shome?cannot/couldn’t have done 过去不可能做了He cannot have forgotten theaccident.may/might have done 也许/或许已经做了It’s too late. I think he may havegone to bed.should/ought to have done 本该做而实际上未做You ought to have done thisexercise more carefully.shouldn’t/oughtn’t to have done 本不该做而实际上做了You shouldn’t have told her thetruth.needn’t have done 本不必做而做了You needn’t have taken a taxi here,because it was very near to myhouse.had better（not）have done 当时最好做了(没做) You had better have finished it ontime.would rather（not）have done 宁愿当时做了（没做）I raised objections at the meeting,but now I would rather not havedone that.would like/love to have done 过去愿意做但未做成I would love to have gone to theparty last night, but I had to workextra hours to finish a report.e.g. (2008, 江苏，35)—I’m sorry. I B at you the other day.—Forget it. I was a bit out of control myself.A. shouldn’t shoutB. shouldn’t have shoutedC. mustn’t shoutD. mustn’t have shouted易错点：1. cannot but+ do sth :不得不/只好做某事e.g. I cannot but choose to go.另外，表达该意思的其他句型有：can’t help but docan’t choose but docan do nothing but dohave no choice but do2. may as well + do: 最好，倒不如e.g. You may as well do it at once.3. should还可用在if 引导的条件状语从句中，表示“万一”e.g. (09天津15) This printer is of good quality. If it _B_ break down within the first year, we would repair it at our expense.A. wouldB. shouldC. couldD. might万一“Why/How should” ,表示说话人对某事不能理解，感到惊讶，意为“竟会”e.g. Why should you be so late today? 你今天怎么来得这么晚？4. must 表示“非要，偏要，硬要”e.g. （2011全国卷二）If you __C___ smoke, please go outside. (如果你非要抽烟，请到外面抽)A. canB. shouldC. mustD. may5. dare/need 做情态动词时，后加do，否定式为daren’t/ needn’t +do做实义动词时，后加to do，否定式为don’t/doesn’t/didn’t + to do自我演练1．We have bought so much food now that Suzie won’t be with us for dinner.A．may not B．needn’t C．can’t D．mustn’t2.-____you interrupt now? Can’t you see I’m o n the phone? ----Sorry Sir, but it’s urgent.A. CanB. ShouldC. MustD. Would3. I’m going to Europe on vacation together with John if I _______ find the money.A. canB. mightC. wouldD. need4. It’s quite warm here; we __________turn the heating on yet.A.c ouldn’tB. mustn’tC. needn’tD. wouldn’t5. I use a clock to wake me up because at six o'clock each morning the train comes by myhouse.A. couldn'tB. mustn'tC. shouldn'tD. needn't6. —Will you read me a story, Mummy? --OK. You ________have one if you go to bed as soon as possible.A. mightB. mustC. couldD. shall7. They _____ have arrived at lunch-time but their flight was delayed.A. willB. canC. mustD. should8. If you __ go, at least wait until the storm is over.A. canB. mayC. mustD. will9. It _______be the postman at the door. It is only six o’clock.A. mustn’t B can’t C won’t D needn’t10. Just be patient. You _____ expect the world to change so soon.A .can’tB .needn’tC .may notD .will not11. --- _____ I take the book out? --- I’m afraid not.A. WillB. MayC. MustD. Need12. -I haven’t got the reference book yet, but I’ll have a test on the subject next m onth.--- Don’t worry. You ____ have it by Friday.A .could B. shall C .must D. may13. Doctors say that exercise is important for health, but it ____ be regular exercise.A .canB .willC .mustD .may14. I have told you the truth. _____ I keep repeating it?A. MustB. Can C .May D .Will15. I’m afraid Mr. Harding _____ see you now. He’s busy.A .can’t B. mustn’t C .shouldn’t D .needn’t。