1、情态动词2dare,need 的用法可兼做行为动词的情态动词：need、dare1.作情态动词用时，常用在否定句和疑问句中。S+neednt+VNeed+S+V?You neednt return the book now.-Need he do it all at once?-Yes,he must.-No,he neednt/doesnt have to.need 的用法2.作实义动词用,有人称、时态、和数的变化。He needs to go there himself.He has grown up,we dont need to worry about him.Do you need
2、to go now?3.(sb.)need to do sth.sb./sth.need(want,require)+doing/to be done We need to know the answer.The house needs cleaning/to be cleaned.The boy needs sending to the hospital at once.1.作情态动词时，主要用在否定句，疑问句及条件句中。S+darent+V dare+S+V?I darent walk through the forest at night.Dare you walk through th
3、e forest at night?If you dare go out,I will kill you.dare/dared 的用法2.作实义动词用,有人称、时态、和数的变化。常见用法是 dare to do,但在否定句和疑问句中，dare to do 中的to可以省略。I dare to swim across this river.He does not dare(to)answer.Dont you dare(to)touch it?情态动词+have done这是历年高考热点之一，表示现在对过去事物的推测，有“推测、责备、怀疑”等多种意义。一、表示对过去事情的推测或估计1.must
4、have done “一定已经”eg:The ground is rather wet,so it must have rained last night.2.may/might have done “可能/大概已经”eg:Tom may have gone to shanghai,but I am still not sure about it.3.cant/couldnt have done“不可能已经”eg:The ground is very dry,so it cant have rained last night注：在疑问句中 can/could 表示对过去情况的疑问性推测，“可能
5、已经？”eg:Someone must have broken into our bedroom.Who could have done it?二、表示对过去所发生事情的遗憾或责备1.should/ought to have done“本该做却没做”eg:I really regretted wasting the hours when I should have studied hard,but it was too late.2.shouldnt/oughtnt to have done “本不该做却做了”eg:Im very sorry for the words I shouldnt
6、have said to you at that moment.3.could/might have done“本可以做却没做”eg:He could have worked out the problem.4.neednt have done“本不必做却做了”eg:Your home is not far from your school,so you neednt have left in such a hurry.5.would rather have done “本想做却未做成”eg:I would rather have come to help you with your Engl
7、ish,but I was too busy at that time.1.The river is rising.It _last night.A.must be raining B.must rain C.might have rained D.must have rained2.I didnt hear the phone.I _asleep.A.must be B.must have been C.should be D.should have been3.-We didnt see Tom at the meeting yesterday.-He it.A.mustnt have a
8、ttended B.cannot have attended C.neednt have attended D.would not have attended4.-There were already five people in the car,but they managed to take me as well.-It _a comfortable journey.A.cant be B.shouldnt be C.mustnt have been D.couldnt have been5.You yesterday if you were really serious about yo
9、ur work.A.ought to comeB.ought to be comingC.ought to have come D.ought have come 6.You _ all these parcels yourself.The shop would have delivered them if you had asked a shop assistant.A.didnt need to carryB.neednt have carried C.neednt carryD.didnt need carry7.Mr.White _ at 8:30 for the meeting,bu
10、t he didnt show up.A.should have arrived B.should arrive C.should have had arrived D.should be arriving8.Ill tell Mary about her new job tomorrow.You _ her last week.A.ought to tell B.would have told C.must tell D.should have told补充：1.Lets do sth,shall we?Let us do sth,will you?2.Please do sth,will you?Please dont do sth,will you?3.had better do sth.would rather do sth.
