1、情态动词和虚拟语气-By Bring Englishcan,could may,might will,would shall,shouldmust,need have to,ought tocant,may not mustnt,needntdont have to shouldnt,shantbe able to dare情 态 动 词1.can,could表示能力He can speak English very well.He could draw very well when he was five.表示许可You can use my computer now.You cant ea
2、t in class.表示请求Can you tell me the way to the post office?Could you show me the way to the Beihai Park?表示猜测Generally,she is a quiet girl.But sometimes she can be talkable.Someone is knocking at the door.Who can it be?It cant be Mr.Zhang.He has gone abroad.The hunters have been lost for days.They cou
3、ld starve.表示惊讶How can she be late for class?She is always on time.2.may,might请求许可May I have a look at your new mobile phone?表示可能The man over there may be your new teacher.He might come here by train or by air.3.will,would表示意愿、倾向On rainy days,she will sit by the window and watch the rain for hours.He
4、 was poor,but he would dress up as a rich man.表示请求Will you please give your seat to the old lady?Would you like to join us for dinner?4.shall用于第一人称，表示将要I shall go with you next time.用于第一人称，表示征求意见Shall I put the book back on the shelf?/Shall we go out for a walk?用于第二、三人称，表示许诺、义务、规定、威胁You shall get a
5、new mobile phone if you pass the exam.Everyone shall wait in line when they buy tickets.According to the agreement,the interest shall be divided equally among the three investors.5.should表示建议（应该）You should lie down and have a rest.表示猜测Its seven oclock.Mr.Li should be there.You have practiced a lot.Y
6、ou shouldnt have any trouble in passing the test.表示惊讶Its surprising that such a pretty girl should be a thief.6.must表示必需We must finish our work by noon.表示猜测There must be something wrong.表示责怪（偏偏，非得）Tom,must you play the piano at this time?My car must break down when I was hurrying to work.7.need表示需要（
7、否定或疑问句）You neednt go to school today.用作实意动词You dont need to go to school today.8.have to表示必需，不得不You have to finish your work by noon.9.ought to表示应该You ought to hand in your homework before school is over.10.dare表示 敢How dare you say that to your mother?She darent go out in the dark.He dared not ask t
8、he teacher for help.用作实意动词He dares to swim across the river by himself.Does he dare to swim across the river by himself?He doesnt dare to swim in the river.注意各种否定式：1.cant I cant play any musical instrument.(不能)It cant be possible.Its so rediculous！(不可能)2.mustntYou mustnt smoke in public places.(千万别)
9、3.may notThat may not be true.(可能不)4.neednt (没必要)5.dont have to(没必要)6.shouldnt(不应该)情态动词+have done1.must have done 一定做过某事2.may/might/could (not)have done 可能(没)做过某事3.cant have done 不可能做过某事4.should(not)have done 本(不)应该做某事5.neednt have done 本没必要做某事6.ought(not)to have done 本(不)应该做某事7.would(not)have done
10、本(不)会做某事虚拟语气一.在条件句中的用法if 从句动词主句动词与现在事实相反过去时（be用were）would/should/could/might+动词原形与过去事实相反过去完成时（had done）would/should/could/might+have done与将来事实相反1.过去时（be 用were）2.should+do3.were+to dowould/should/could/might+动词原形1.If I were you,I would ask the teacher for advice.If he knew the truth,he would tell you
11、.2.If you had come earlier,you would have met the famous star.She wouldnt have been so angry if you had apologized to her.3.If it were to snow this evening,they would/should/could/might not go out.If it should break down within one year,we would repair it at our expense.If you went there,I would/sho
12、uld/could/might go with you.需要注意的问题1.错综条件句 If you had followed my advice,you would do it better now.If I were you,I wouldnt have missed the film last night.2.倒装句（省略if）Were she older,she would do it.Should he come,tell him to ring me up.Had we taken the taxi,we wouldnt have been late for the meeting.
13、二.介词短语等代替条件从句Without air,there would be no living things.But for your help,we wouldnt have finished the task on time.三.根据上下文判定1.I would have come to your party,but I was too busy last night.2.I was too busy last night,otherwise I would have come to your party.3.You were driving too carelessly,otherw
14、ise you wouldnt be in hospital now.四.在其他从句中的 虚拟语气1.I wish I had my own company.I wish I would travel in space some day.I wish I had known you earlier.2.I would rather you came here tomorrow.I would rather I hadnt seen the film.3.He talks as if he knew everything.He talks as if he had been to the moon.4.He suggested/ordered/requested.that.(should)do.5.It is important/strange/necessary that.(should)do.6.It is commanded/suggested/required that.(should)do.7.The requirement is that.(should)do.8.We all agreed to the suggestion/request/adviece that.(should)do.
