1、情态动词情态动词基本用法你能说出哪些情态动词1.can/could2.may/might3.should/ought to4.need5.must6.will/would/shall7.dare情态动词的用法1.情态动词不能单独使用，必须放在谓语动词之前2.情态动词后的谓语动词必须用原型3.变否定直接在情态动词后加not4.变一般疑问句，直接把情态动词提到句首情态动词表推测对比-表达“也许，大概，可能，一定”等意思都是表示推测1.must:表“一定”，常用语肯定句中举个栗子：They must be anxious to learn about local customs.2.can/coul
2、d:表“可能”，用于疑问句；cant/couldnt,表“不可能”，用于否定句中,举个栗子：-Can what he said be true?-No,what he said cant be true.再举个栗子：-Can she be in the parade now?-No,she cant.It cant be the postman at the door.Its only six oclock.情态动词表推测对比3.may/might:表“可能”,用于肯定句；may not/might not,表”可能不”，用于否定句举个栗子：She is coming.She may/migh
3、t be our new teacher.There may/might not be any ink in the bottle.总结：句型情态动词中文含义肯定句must一定may/might可能否定句cant/couldnt不可能，一定不may not/might not可能不疑问句can/could.可能.吗？不同时间的推测对现在（常态）或将来事情的推测：情态动词+do对正在发生的事情的推测：情态动词+be doing对过去发生事情的推测：情态动词+have done举个栗子：It must often rain here in spring.(对常态的推测）It may rain to
4、morrow,for there is no stars in the sky tonight.Listen to the sound.It must be raining outside.The road isnt wet.It cant have rained last night.情态动词表请求，许可：可以吗？可以呀！句式情态动词中文意思区别疑问句Can/Could/May/Might.?可以.吗？能.吗？委婉性：couldcanmightmay场合：can/could-口语may/might-正式肯定句can/could/may/might可以同上;一般疑问句的肯定回答用can/may
5、否定句mustnt/cant/couldnt/may/might not不可以同上；一般疑问句的否定回答用cant/mustnt举个栗子：1.-May/Might I come into the room to see my mother?-Yes,you can.-No,you cant/mustnt.2.You may/might/can/could/must not leave the reading room till you return the book.3.-Could/Can I borrow your dictionary?-Yes,you can.No,you cant/m
6、ustnt.4.Visitors cant litter the ground with paper.情态动词can/could的其他用法1.表能力，“能，会”，此时could时can的过去式举个栗子：I can speak English and French,but I cant speak Japanese.By the time she was eight,she could play several instruments.2.表“一时之可能性”，常与 sometimes，或at times连用举个栗子：It is usually warm in my hometown in Mar
7、ch,but it be rather cold sometimes.can情态动词may的其他用法1.用于祈使句中，表祝愿举个栗子：May you succeed!May God bless you!情态动词must的其他用法1.表“必须”举个栗子：Everybody must obey the rule.-Must I do as I am told?-Yes,you must.No,you neednt/dont have to.2.mustnt 表“禁止”举个栗子：Father is sleeping.You mustnt wake him up.3.表“偏要，偏偏要”，指做令人不愉快
8、的事情举个栗子：Why must you always interrupt me?句式情态动词中文疑问句Must.必须.吗？肯定句must必须否定句neednt/dont have to不必要，不需要其他情态动词的用法-should1.should 表“应该”=ought to举个栗子：You shouldnt paly a trick on her.You know she is a sensitive girl.2.should 表“竟然”，表示惊讶，难以置信的情绪举个栗子：Its strange that he should believe the prediction.The man
9、should enter the danger zone with permission.有题有真相：It was sad to me that they,so poor themselves,bring me food.should其他情态动词的用法-will/would1.表“会，愿意”举个栗子：I will support you forever whatever happens.Will you marry me?2.表“注定会.”举个栗子：Man will die without water.Oil will float on water.3.would表“过去常常做”，且现在也可能
10、还在进行。其他情态动词的用法-shall1.表征求对方意见的疑问句中，此时句子主语必须是第一，或第三人称Shall we go to the cinema tonight?Shall Tom go with us?2.表说话人给对方的许诺，命令，警告等。此时句子主语是第二，第三人称。-I havent got the reference book yet,but Ill have a test on the subject next month.-Dont worry.You shall have it by Friday.3.表条约，规定中的义务或责任，翻译为“应当，应该”，此时主语为第三人
11、称.Students shall wear school uniforms in the school.其他情态动词的用法-need&dare(情态动词的两大叛徒）判断下列句子的正误。He need not go now.He need not to go now.He doesnt need go now.He doesnt need to go now.need作实意动词，”需要做某事”need to do sthdare作实意动词，“敢做某事”dare to do sth情态动词+have done情态动词的虚拟语气情态动词的虚拟语气-情态动词+have done情态动词+have do
12、ne:表示与过去事实相反的虚拟语气有题有真相1.We（face)the difficulty together,but why didnt you tell me?They（arrive)at lunchtime but their flight was delayed.3.We（not wait)for him.We wasted a whole afternoon.should(not)have done=ought(not)to have done过去本(不)应该做某事would(not)have done过去本(不)会做某事could(not)have done过去本(不)可以做某事m
13、ight(not)have done过去本(不)可能做某事need(not)have done过去本(不)有必要做某事could have facedwould have arrivedneednt have waited举个栗子：1.He used to be very rich but something must have happened to him.2.I shouldnt have watched that moive-itll give me horrible dreams.3.Without their help,I couldnt have won the prize.Or they could have gone exploring on their own and lost their way back to the group.4.The children might have arrived there by now.5.I would rather have gone to the moive yesterday.
