仁爱版英语八年级上册情态动词讲解（课堂PPT）

1、情态动词情态动词2 2定义：情态动词具有情态意义，即它所表示的情态动词具有情态意义，即它所表示的是说话人对动作的观点，如需要、可能、是说话人对动作的观点，如需要、可能、意愿、或怀疑等。意愿、或怀疑等。3 3特征：1.在形式上，情态动词不像实义动词那样有各种变化，只有could，would，had to，might等几个过去式。其它如must，ought to等表示过去时形式不变。2.在意义上，大多数情态动词有几多个意义：如can表示“能够”，“可能”，“允许”等；may 可表示“可能”“允许”“目的”“让步”等。3.情态动词没有人称和数的变化，适用于各种人称。4.情态动词后加动词原形构成谓语部

2、分。4 4can/couldcan/couldCan表示能力，许可，可能。Could 是can 的过去式，表示过去的能力。Could表示可能时，比can 所表示的可能性小，表示请求允许和许可时，可以代替can，意为“可以”，语气更为委婉。5 5can的用法1.表示能力。如：We can carry the heavy box. 我们可以搬得动箱子。Who can sing an English song?谁会唱英文歌？2.表示惊讶、不相信等态度，主要用于否定句和疑问句中。（猜测）如：Can it be true? 这会是真的吗？You cant be serious? 你不会当真吧？ 3.表示

3、允许，意思与may相近，主要用于口语中。如：Can I smoke here? 我可以在这儿吸烟吗6 6could1)提出委婉的请求，（注意在回答中不可用could）。例如：CouldIhavethetelevisionon?我能看电视吗？Yes,youcan./No,youcant.可以/不可以。(2)在否定句、疑问句中表示推测或怀疑。例如：Hecouldntbeabadman.他不大可能是坏人。7 7 所有的can、could与be able to区别； 区别：can、could强调的是天生的能力；(与生俱来的) be able to表示设法做成某事；(通过后天的努力)cant + too

4、 +adj.表示再也不过分Eg: You cant be too careful when crossing the road. 译文：当你过马路的时候，再怎么小心也不过分8 8may/might1.表示可能但不肯定，通常用于肯定陈述句，暗含不确定。而might 比may 的可能性小，更具有不确定性。如：He may arrive tomorrow。9 92.表示允许或征求同意，多用于肯定句和疑问句。在提出请求时，might 比may 语气更委婉，更有礼貌。May I put here？Might I use your phone？3.句型can/may/could/might I ?表示请求

5、对方许可，其中can语气最不正式，could语气比较客气，委婉，may/might 用于正式场合，语气恭敬，might比may更为客气。肯定回答：of course，you can/may否定回答：no，you cant/may not(不用could或might)10104.表示祝愿May you happy everyday!祝你开心每一天！1111mustmust1212基本用法：1.表义务，可用于肯定句和疑问句。You must take care of your parents.2.must的否定式，表示不许，禁止，如：You mustnt park here.3.表示推测，暗含很大

6、的可能或符合逻辑，只用于肯定句。如：You must be hungry now。The letter must be from her pen pal。13134.表示劝告，必须做某事，表明事情的必要性与重要性。如：You must wear a coat。 5.回答带must 的疑问句时，要用neednt或dont have to来作为否定回答，不能用，mustnt。如：Must we keep the window open all the time？- No，you dont have to/No，you neednt.1414Must 和 have to的区别1.must 和have

7、 to都有必须的意思。但是，must强调说话者主观的看法，而 have to 强调客观的需要。例：I must leave now.（我想走）I have to cook for my grandfather(爷爷年纪大生病了等客观原因)2.must 没有过去式，而had to 表示过去已实现的动作。I had to borrow some money at that time.1515shall表示征询意见，用于第一人称的疑问句中如：Shall we take you to the hospital?What shall we do this weekend? 1616should“应该”学

8、会使用should作为情态动词用，常常表示意外、惊奇、不能理解等，有“竟会”的意思， 例如：How should I know? 我怎么知道？ Why should you be so late today? 你今天为什么来得这么晚？should 常用来表示劝告、建议、认为某人“应该、应当”做某事，或“有责任和义务”做某事1用于表示“应该”或“不应该”的概念。此时常指长辈教导或责备晚辈。例如：You should be here with clean hands. 你应该把手洗干净了再来。2. 用于提出意见劝导别人。例如：You should go to the doctor if you f

9、eel ill. 如果你感觉不舒服，你最好去看医生。 1717need1.need作实义动词，意为“需要”。如：need to do sth.eg. Do you need to stay at home?你要呆在家里吗？2.need作情态动词，一般用于对must的否定回答。如：-Must he leave now?他必须离开吗？-No, he neednt.不，他不必。18183.区分：a.needa.need作作实义动词实义动词。He needs to go.He needs to go.He doesnt need to go.He doesnt need to go.Does he n

10、eed to go?Does he need to go? Yes, he does./No, he doesnt. Yes, he does./No, he doesnt.b.needb.need作作情态动词情态动词，一般不用于肯定句。，一般不用于肯定句。He neednt go.He neednt go.Need he go?Need he go? Yes, he need./No, he neednt. Yes, he need./No, he neednt.19192020l练习1_IwaterthetreesonTuesday?No,youneednt.A.CanB.MustC.Ma

11、yD.Shall2._Iturnontheradio?Youdbetternot.Itisnoisyenoughinthisroom.A.ShallB.MustC.NeedD.Do3Letsgotothelibrarythisafternoon,_?A.shallweB.willweC.canweD.shouldwe4.Everyone_dohisbesttomaketheworldclean.A.canB.mayC.shouldD.hadto5._tohavelunchwithustoday?A.DoyoulikeB.WouldyoulikeC.WillyoulikeD.Haveyoulik

12、e21216Willyoulendmeyourbook?Yes,I_.A.willB.needC.canD.must7.He_tothefarmyesterday.A.needgoB.neededgoC.hastogoD.hadtogo8.You_tothemeetingthismorningifyouhavesomethingimportanttodo.A.neednttocomeB.dontneedcomeC.dontneedcomingD.needntcome222211You_getdownthebusuntilthebushasstopped.A.cantB.needntC.must

13、ntD.dont12.Shelookssosad.She_ill.A.canbeB.shouldbeC.mustbeD.willbe13.Iwanttogotothehospital,butyou_withme.A.needtonottogoB.donotneedgoC.neednotgoD.needgonot14Mary_beinLondonbecauseIsawherintownjustnow.A.mustntB.isntabletoC.maynotDcannot232317John_cometoseeustonight,butheisntsureyet.A.mayB.canC.hasto

14、D.must18They_dowellintheexam.A.canbeabletoB.beabletoC.canabletoD.areableto19-MayItakethisbookout?-No,you_.A.cantB.maynotC.needntD.arent20You_goandseeadoctoratoncebecauseyougotafever.A.canB.mustC.dareD.would242421-Can you speak Japanese? -No, I_. A. mustnt B. cant C. neednt D. may not22-He_ be in the

15、 classroom, I think. -No, he _ be in the classroom. I saw him go home a minute ago. A. can; may not B. must; may notC. may; cant D. may; mustnt 23 -Shall I get one more cake for you, Dad? -Thanks, but you_, I had enough. A. may not B. must not C. cant D. neednt 252524.Even the top students in our cl

16、ass cant work out this problem, so it_be very difficult. A. may B. must C. can D. need 25. He isnt at school. I think he _ be ill. A. can B. shall C. must D. has to 26 -Must I do my homework at once? -No, you_. A. neednt B. mustnt C. cant D. may not 27 His arm is all right. He_ go and see the doctor. A. has not to B. dont have to C. havent to D. doesnt have to 2626选择合适的情态动词填空（should,may,can,must)1.Itisrainingoutside.You_stayherealittlel