情态动词guess.ppt

1、Grammar,情态动词,非推测性情态动词shall, will, must, mustnt, should, would的用法,情态动词could, should/ought to, may/might , neednt+ have done 表示假设的用法,情态动词must, can/could, may/might, should/ought to表猜测的用法,情态动词的一些惯用法,表示推测情态动词的重要用法.,肯定的推测 可能的推测 否定的推测 疑问的推测,must,对将来 对现在 对过去,情态动词,may, might,cant, couldnt,can, could,+ V. +

2、V. + have done 常见must be + be doing,+ V. + V. + have done + be doing 可以用not表示“可能不”,+V. + V. + have done + be doing,+ V. + V. + have done + be doing,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/一定作了某事”。,1.We must have learned 2,000 words by the end of last term. 到上学期为止我们一定学了有两千个单词 。 2.He must have gone

3、to Beijing. 他一定已经去北京了。,can/could+have done表示对过去的行为的怀疑和不肯定，通常用在否定句和疑问句中。,1. Can they have won the basketball match? 他们可能赢了篮球赛吗？ 2. It couldnt have been Mr. Green. He has gone to New York. 那不可能是格林先生的，他已经去北京了。,could(不用can)+have done,在肯定句中表示“本来能够而没能”，具有婉转的批评和责备之意。,You could have told me earlier. 你本该早点告诉

4、我的。,should/ought to+have done用于肯定句时，表示“本该做某事而实际上没做”，用于否定句时，则表示“不该做的事反而做了”。,1.You should have told him a week ago. 你本来应该在一周前告诉他的。,might（不用may）+have done表示“本来可能”，但实际上没有发生的事。另外，还可表示“本来应该或可以做某事”之意，含有轻微的责备语气。,1.You might not have told her. 你本可以不告诉他的。（事实上你告诉他了） 2. You might have come earlier. 你本可以早点来的。（但没

5、有这样）,neednt +have done表示做了本来不必去做的事。,1.She neednt have gone to the station yesterday. 昨天她本不必到火车站去的.（昨天她去了） 2.You neednt have bought it. 你本可不必买它的。 （你买了）,巩 固 练 习,1.Oh, Im not feeling well in the stomach. I _ so much fried chicken just now. A. shouldnt eat B. shouldnt have eaten C. mustnt eat D. mustnt

6、have eaten 2.-Why hasnt Jane arrived yet? -She _ again in the morning? A. shouldnt have overslept B. may have turned off the alarm clock C. must have no one t o call her D. should have someone to wake her up 3.-Did you go to the movie the day before yesterday? -No. We _, but we decided not to. A.sho

7、uld have gone B. could go C. should go D. could have gone,B,B,A,4.As it turned out to be a small house party, we _ so formally. neednt dress B. didnt have to dress up C. Might not have dressed up D. neednt have dressed up 5.Im rather surprised you havent reported him to your teacher. In my opinion,

8、you _ this as soon as you found out he was cheating. must have done B. might have done C. should have done D. could have done,D,C,1.作为情态动词用，常用在否定句和疑问句中。,Dare (need) +S +V S + darent (neednt) +V,I darent walk through the forest at night. Dare you walk through the forest at night? You neednt return th

9、e book now. Need he go yesterday?,可兼做行为动词的情态动词：need 、 dare,2.作实义动词用，常用在肯定句中, 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.,3.Sth (sb) need( want, request)+ doing/ to be done The house needs cleaning/ to be cleaned The boy needs sending to the hospital at

10、 once.,句型 时态 动词 情态动词dare 实义动词 dare 肯定句 现在时 dare do dare/dares to do 过去时 dare do dared to do 否定句 现在时 darent/dare not do do/does not dare (to) do 过去时 dared not do did not dare (to) do 疑问句 现在时Dare he do? Do you/Does he dare (to) do? 过去时 Dared he do? Did he dare (to) do,2.I wonder how he_that to the tea

11、cher. A. dare to say B. dare saying C.not dare say D.dared say,D,4.As it turned out to be a small house party, we _ so formally. A neednt dress B. didnt have to dress up C. Might not have dressed up D. neednt have dressed up,D,1.判断正误:,How dare you say such a thing? How dare you to say such a thing?,

12、He darent to speak English before such a crowd, did he? He darent speak English before such a crowd, dare he?,Exercises,Nobody need to be afraid of catching the disease. Nobody need be afraid of catching the disease.,These dishes need be cleaned carefully. These dishes need to be cleaned carefully.

13、These dishes need cleaning carefully.,hadbetter(最好),should(应该)与oughtto（应该）均为提建议、阐述观点的情态动词，其后接动词原形。should比hadbetter语气强，oughtto语气最强。一般情况下should与oughtto可通用。 例1：你最好立即去那里。 Youhadbettergothereatonce. 例2：你应该努力工作。 Yououghtto/shouldworkhard.,（一）否定句hadbetter,should,oughtto用于否定句时，否定词均位于其后，具体形式为：hadbetternotdo,

14、shouldnt/shouldnotdo, oughtnttodo。例1此时你最好别出发。： Youhadbetternotstartatthistime. 例2：她不应该浪费时间。 Sheoughtnttowastetime.,（二）一般疑问句hadbetter,should,oughtto用于一般疑问句时，分别将had,should,ought提至句首。例1：他最好立即出发吗？ Hadhebetterstartearlyatonce? 例2：你应该这么做吗？ Shouldyoudolikethis? 例3：他应该去那里吗？ Oughthetogothere?,（三）反意疑问句陈述句谓语动词

15、含hadbetter,should,oughtto时，反意疑问句为：had,should与ought+主格人称代词或hadnt,shouldnt,oughtnt+主格人称代词。例1：你最好别回家，是吗？ Youhadbetternotgohome,hadyou? 例2：你应该认真学习，是吗？ Youshouldstudyhard,shouldntyou? 例3：你上课不应该讲话，是吗？ Heoughtnttospeakinclass,oughthe?,1The flower is dead. I _ it yesterday. Ashould water Bmust water Cshould have watered Dmustnt have watered 2What time ought I _? Aarrived Barriving Carrive Dto arrive 3He _ speak to his mother like th