初中英語(yǔ)情態(tài)動(dòng)詞專項(xiàng)講解

1、初中英語(yǔ)情態(tài)動(dòng)詞用法詳解【情態(tài)動(dòng)詞知識(shí)梳理】情態(tài)動(dòng)詞有具體的詞義，但也同助動(dòng)詞一樣，需要與其他詞語(yǔ)一起構(gòu)成句子的謂語(yǔ)，另外情態(tài)動(dòng)詞沒有人稱和數(shù)的變化，情態(tài)動(dòng)詞后必須跟動(dòng)詞原形?？键c(diǎn)一：can，may，must等情態(tài)動(dòng)詞在陳述句中的用法：1. can的用法：（1）.表示能力、許可、可能性。表示能力時(shí)一般譯為“能、會(huì)”，即有種能力，尤其是生來(lái)具備的能力，此時(shí)may和must均不可代替它。She can swim fast, but I cant . 她能游得很快，但我不能。I can see with my eyes.我用眼睛看。（2）.表示許可，常在口語(yǔ)中。You can use my dict

2、ionary. 你可以用我的字典。（3）.表示推測(cè)，意為“可能”，常用于否定句和疑問(wèn)句中，此時(shí)cant譯為“不可能”。Can the news be true ? 這個(gè)消息會(huì)是真的嗎？Can it be our teacher ? 那個(gè)人有可能是我們老師嗎？No, it cant be our teacher. He is on a visit to the Great Wall.不可能。咱們老師正在游覽長(zhǎng)城呢?！纠}】I think Miss Gao must be in the library. She said she would go there.No. She _be there,

3、I have just been there. A. cant B. mustnt C. neednt D .wouldnt【解析】根據(jù)下文“我剛?cè)ミ^(guò)那兒”可知，應(yīng)為“不可能”，cant表示推測(cè)答案 A2. could的用法：（1）.can的過(guò)去式，意為“能、會(huì)”，表示過(guò)去的能力。He could write poems when he was 10. 他十歲時(shí)就會(huì)寫詩(shī)。（2）. could在疑問(wèn)句中，表示委婉的語(yǔ)氣，此時(shí)could沒有過(guò)去式的意思。Could you do me a favor? 你能幫我個(gè)忙嗎？Could I use your pen? 我能用一下你的鋼筆嗎?Yes, yo

4、u can.可以。（注意回答）3. may的用法：（1）.表示請(qǐng)求、許可，比can正式，May I borrow your bike?我可以借你的自行車嗎？You may go home now.現(xiàn)在你可以回家了?！纠}】_ I borrow your MP3?Sure . Here you are. A. May B. Should C. Must D. Would【解析】在此處表示請(qǐng)求，意為“做可以嗎”。答案：A (2) .表示推測(cè)，談?wù)摽赡苄裕鉃椤翱赡?，或許”，一般用于肯定句中。It may rain tomorrow .明天可能會(huì)下雨。She may be at home.她可能在家

5、呢. (3) .may的過(guò)去式為might，表示推測(cè)時(shí)?？赡苄缘陀趍ay。He is away from school. He might be sick.他離開學(xué)校了，可能是他生病了。 (4) . 表示希望、祈求、祝愿，?？勺g為“祝愿”。通常是用may +主+VMay you have a good time.祝你過(guò)得愉快。May you be happy!祝你幸福！May you succeed！祝你成功！4. must的用法：(1).must表示主觀看法，意為“必須、一定”。You must stay here until I come back. 在我回來(lái)之前你必須呆在這兒。Must

6、I hand in my homework right now? 我必須現(xiàn)在交作業(yè)嗎？(2)其否定形式mustnt表示“一定不要” “千萬(wàn)別” “禁止,不許”.You mustnt play with fire. 你不許玩火。You mustnt be late.你一定不要遲到。（3）對(duì)must引導(dǎo)的疑問(wèn)句， 肯定回答為must，否定回答為neednt 或dont have to Must I finish my homework ? 我現(xiàn)在必須完成作業(yè)嗎？No, you neednt.不，你不必。 (4) must表示有把握的推測(cè)，用于肯定句。The light is on, so he m

7、ust be at home now.燈亮著，他現(xiàn)在肯定在家。注意其反意問(wèn)句的構(gòu)成形式：當(dāng)must表示肯定的判斷、推測(cè)時(shí)，其反意疑問(wèn)句要用實(shí)際問(wèn)句的助動(dòng)詞來(lái)構(gòu)成。She must have seen the film before，hasnt she? (注意反意疑問(wèn)句的后半部分)You must have met uncle Wang in the shop yesterday，didnt you? (注意反意疑問(wèn)句的后半部分)5. need的用法：（1）.need表示需要、必須，主要用于否定句和疑問(wèn)句中，其否定形式為neednt，意為“沒有必要，不必”。用need提問(wèn)時(shí)，肯定回答為must

8、，否定回答為neednt或dont have to。Need I stay here any longer? 我還有必要留在這兒?jiǎn)?？Yes, you must .是的。No. you neednt /dont have to.不，你不必。(2).need還可以作實(shí)義動(dòng)詞，此時(shí)有人稱、數(shù)和時(shí)態(tài)的變化，如果是人作主語(yǔ)后邊多接動(dòng)詞不定式。I need to do it right now.我需要馬上做這件事。He needs to learn more about the girl.他需要多了解那個(gè)女孩。如果是物作主語(yǔ)，一般用need doing與need to be done這種情況下應(yīng)注意兩點(diǎn)：

9、. 主動(dòng)形式的動(dòng)名詞doing具有被動(dòng)的含義；.該動(dòng)名詞可以改為其動(dòng)詞不定式的被動(dòng)形式而句子的意義不變。.The door needs painting. = The door needs to be painted.那扇門需要油漆一下。Your car needs mending. = Your car needs to be repaired.你的車需要維修了。6. dare的用法：dare意為“敢、敢于”,用法近似于need，有兩種詞性：（1）dare作為情態(tài)動(dòng)詞，多用于否定句、疑問(wèn)句或條件句中，無(wú)第三人稱單數(shù)形式，只有一般現(xiàn)在時(shí)和一般過(guò)去時(shí)。Dare he tell them what

10、 he knows ? 他敢告訴他們所知道的情況嗎？I darent ask her will you do it for me ? 我可不敢問(wèn)她，你能幫我問(wèn)問(wèn)嗎？（2）dare作為實(shí)義動(dòng)詞，此時(shí)有人稱、數(shù)及時(shí)態(tài)的變化。He doesnt dare to break his promise.他不敢食言。注意：在口語(yǔ)中，dare的各種形式常與不帶to的不定式連用。Do you dare tell her what I said? 你敢告訴她我說(shuō)的話嗎？I didnt dare look at him. 我不敢看他。7. shall的用法：shall表示征求對(duì)方意見（多用于第一、三人稱），Shal

11、l we go out for a walk?我們出去散步好嗎？在英語(yǔ)中，我們可以用其他多種方式提出我們的建議或征求對(duì)方意見。(1).用“Lets do.”來(lái)提出建議。Lets go for a walk after supper.(2).用“What/How about.?”來(lái)提出建議；about后接名詞或動(dòng)詞ing形式。What about/How about a drink? What about/How about taking Tom with us?(3).用“Why not.?”來(lái)提出建議，表示“何不”not面后接動(dòng)詞原形?！癢hy not.?”實(shí)際上是“Why dont you

12、/we.?”的簡(jiǎn)略形式。Why not meet at the school gate at eight? Why dont we stay here another day?(4).用“Would you like.?”來(lái)提出建議，意思是“你想要嗎?”Would you like后可接名詞或不定式。Would you like a cup of tea?Would you like to go and see her?因此，如果我們說(shuō)：“去游泳好嗎?”英語(yǔ)中可有這樣幾種表達(dá)法：Shall we go for a swim?Lets go for a swim，shall we?What ab

13、out/How about going swimming?Why not go for a swim?Would you like to go for a swim?What do you think of going for a swim?8. should的用法：（1）.should意為“應(yīng)該”，可表示勸告、建議、義務(wù)、責(zé)任等。We should protect the environment.我們應(yīng)該保護(hù)環(huán)境。（2）Should have done表示對(duì)過(guò)去動(dòng)作的責(zé)備、批評(píng)。You should have finished your homework.你應(yīng)該已經(jīng)完成作業(yè)了。（事實(shí)上你沒有

14、完成。）9. will的用法：will表示意愿、意志、打算，可用于多種人稱。I will help you if Im free this afternoon.今天下午如果我有空，我就會(huì)幫你。注意：1、will在there be句型中的形式及其句式變換。由于“一般將來(lái)時(shí)”的結(jié)構(gòu)可以用“will+動(dòng)詞原形”來(lái)表示，所以there be句型的一般將來(lái)時(shí)的形式就是there will be。（一定不能說(shuō)there will have）There are many students in our school.There will be many students in our school. The

15、re will be a sports meeting next week.一定不能說(shuō)：There will have a sports meeting next week.2、will與be going to do something區(qū)別：. be going to表示近期、眼下就要發(fā)生的事情，will表示的將來(lái)時(shí)間則較遠(yuǎn)一些，He is going to write a letter tonight. He will write a book one day. be going to表示根據(jù)主觀判斷將來(lái)肯定發(fā)生的事情，will表示客觀上將來(lái)勢(shì)必發(fā)生的事情。He is seriously i

16、ll. He is going to die. He will be twenty years old. be going to含有“計(jì)劃，準(zhǔn)備”的意思，而will則沒有這個(gè)意思，She is going to lend us her book.He will be here in half an hour.在有條件從句的主句中，一般不用be going to,而多用will, If any beasts comes at you, Ill stay with you and help you.10. had better的用法：had better意為“最好”，沒有人稱的變化，后面接不帶to

17、的不定式，其否定形式為：had better not。We had better go now.我們最好現(xiàn)在就走。You had better not give the book to him.你最好不要把這本書給他?？键c(diǎn)二：含有情態(tài)動(dòng)詞的疑問(wèn)句的回答:1. 對(duì)may引出的問(wèn)句，可以有下列回答方式：Yes, you may. | 、 Yes, of course.、 Yes, certainly.、 Sure .No, you mustnt. 、 No, you cant.2.對(duì)must引出的疑問(wèn)句，回答方式為：Yes, must. 、 No, neednt/ dont have to.3.c

18、ould在疑問(wèn)句中，表示委婉的語(yǔ)氣，此時(shí)could沒有過(guò)去式的意思。Could you do me a favor ? 你能幫我個(gè)忙嗎？Could I use your pen?我能用一下你的鋼筆嗎?Yes, you can.可以。（注意回答）4. shall引出的疑問(wèn)句用于第一人稱，表示征求對(duì)方意見或客氣的請(qǐng)求。其回答方式有以下幾種：Yes, please .、All right .、No, thank you.5. would you的回答方式有以下幾種：Yes, I will. (No, I wont.)、Sure . (Im sorry , I cant.)、All right/ OK

19、/ With pleasure.、Certainly. (No, thank you .)、Yes, please.【例題】Would you do me a favor and pass on my thanks to Lily?_.A.Thats right B.With pleasure C.It doesnt matter D.No trouble【解析】A.意為“對(duì)了”，B.意為“樂意效勞”, C.意為“沒關(guān)系” D.意為“不費(fèi)事”。答案：B考點(diǎn)三:不同情態(tài)動(dòng)詞的否定意義也不同：1.（1）.cant可譯為“不會(huì)”，I cant play basketball.我不會(huì)打籃球。（2）當(dāng)句

20、子表推測(cè)時(shí)，用cant表達(dá)不可能，He cant be ill. He is playing chess with Tom.他不可能病了，他正和Tom下棋呢。（3）cant還可用來(lái)回答“ May I ? ”這樣的問(wèn)句。May I come in ? 我可以進(jìn)來(lái)嗎？ No, you mustnt. / cant.不，你不能。（4）cant還可用于固定習(xí)語(yǔ)中。cant help doing禁不住，情不自禁cant wait to do something迫不及待地要做She cant help crying.她不禁大哭起來(lái)。The children cant wait to open the bo

21、x.孩子們迫不及待地想打開盒子。2. may的否定式為may not，譯成“可能不”，He may not be at home.他也許不在家。3.（1）mustnt表示不許，不可。He mustnt leave his room.他不許離開他的房間。You mustnt talk in class.你們不可以在課上說(shuō)話。(2) mustnt也可用于以may表示要求時(shí)的否定回答中。May I stand here? 我可以站在這里嗎？No, you mustnt (cant).不，不行。4.（1）neednt意為“不必”。You neednt meet him unless youd like

22、 to.你不需要見他，除非你愿意。（2）neednt + have+動(dòng)詞的過(guò)去分詞，表不需要完成但已完成的動(dòng)作，暗含時(shí)間或精力上的浪費(fèi)。You neednt have bought it.你沒必要買它（但你卻買了）。5. shouldnt表示不應(yīng)該。You shouldnt feel so unhappy over such little things.對(duì)于這種小事，你不應(yīng)該感到這么不高興?？键c(diǎn)四:情態(tài)動(dòng)詞的被動(dòng)語(yǔ)態(tài)含有情態(tài)動(dòng)詞的被動(dòng)語(yǔ)態(tài)的結(jié)構(gòu)為：情態(tài)動(dòng)詞+ be + done (動(dòng)詞的過(guò)去分詞)。做題時(shí)要兼顧情態(tài)動(dòng)詞和被動(dòng)語(yǔ)態(tài)這兩個(gè)方面。You neednt get up so early

23、every day.你不必每天都起這么早。She shouldnt speak to her mother in that way.她不應(yīng)該用那種方式和媽媽說(shuō)話。More and more trees must be planted in China.在中國(guó)必須種植更多的樹木。Many of the stars can not be seen because they are far away from us.很多星星我們都看不到，因?yàn)樗鼈冸x我們太遠(yuǎn)了?？键c(diǎn)五:情態(tài)動(dòng)詞表示推測(cè)的用法:一、“情態(tài)動(dòng)詞+動(dòng)詞原形”表示對(duì)現(xiàn)在的推測(cè)。1、can表示推測(cè)時(shí)一般用于否定句或疑問(wèn)句。That man ca

24、nt be her husband she is still single.Who is knocking at the door?Can it be the postman?2、must表示肯定的推測(cè)，一般用于肯定句中。He must be in his office now. Mr Li must be working now，for the lights in his office are still on.3、might表示推測(cè)時(shí)不一定是may的過(guò)去時(shí)，只是表示其可能性較小。The man may be the headmaster.Where is Mr Li?He might be

25、 working in his office. May Mr Li come?He might not come here.4、Could表示推測(cè)時(shí)，語(yǔ)氣can比要弱，說(shuō)話者留有余地。Could it be an animal?It could not be，because it is not moving.5、Should表示推測(cè)的可能性比較大，僅比must的可能性小一點(diǎn)。It is already 10 oclock now they should be there.二、情態(tài)動(dòng)詞表示對(duì)過(guò)去可能發(fā)生的動(dòng)作或存在過(guò)的動(dòng)作的推測(cè)性用法。1、“must +have done/been-”表示“過(guò)去

26、一定發(fā)生過(guò)某事或存在過(guò)某種狀態(tài)”，不用于“musnt+have-”形式。如：She must have seen the film before，hasnt she?(注意反意疑問(wèn)句的后半部分)You must have met uncle Wang in the shop yesterday，didnt you? (注意反意疑問(wèn)句的后半部分)2、“should +have done /been-”表示“本應(yīng)當(dāng)做某事，而實(shí)際上并沒有做”；“shouldnt+完成式”表示“本來(lái)不應(yīng)當(dāng)做，而實(shí)際上卻做了”。以上結(jié)構(gòu)常帶有說(shuō)話者的 責(zé)備的感情色彩。You should have finished y

27、our homework earlier (but in fact you did not finish it on time).You shouldnt have gone to bed when you woke up at five (but in fact you went to bed again then).3、“neednt+完成式”表示“本來(lái)沒有必要做某事，而實(shí)際上卻做了”。There was plenty of time. She neednt have hurried .4、“cant /couldnt+have done /been-”表示“過(guò)去不可能發(fā)生了某事或存在過(guò)某

28、種狀態(tài)”。I saw him just now. He cant have gone to Japan.She said the man couldnt have stolen her car.5、“could +have done/been-”表示“過(guò)去本來(lái)能夠，可以做某事或成為某種狀態(tài)，而實(shí)際上沒有”，說(shuō)話者有些遺憾?！癱ould sb. have done /been-？”是它的問(wèn)句形式。You could have stayed with the Smiths while you were in New York (but in fact you stayed in a nearby

29、hotel .) Could Mr Li have helped this girl student?6、“may/might+完成式”表示“過(guò)去可能，本來(lái)可以于某事而實(shí)際上沒有干”，might的可能性較小，語(yǔ)氣較弱。如：He may have finished reading the book. She might have given you some help，however bus she was.【情態(tài)動(dòng)詞易混點(diǎn)歸納】易混點(diǎn)一: can和be able to:兩者表示能力時(shí)用法相同，但can只有原形“can”和過(guò)去式“could”兩種形式，在其他時(shí)態(tài)中要用be able to來(lái)表示。

30、另外be able to常常指經(jīng)過(guò)努力，花費(fèi)了時(shí)間和勞力之后才能做到某事。如：Jim cant speak English.吉姆不會(huì)說(shuō)英語(yǔ)。He could speak English at 5.他五歲時(shí)就會(huì)說(shuō)英語(yǔ)。Well be able to see him next week.下星期我們將會(huì)見到他。He has been able to drive.他已經(jīng)會(huì)開車了。Im sure youll be able to finish it quickly.我相信你能迅速地完成。We were able to reach the top of the mountain at noon.我們能在中

31、午到達(dá)山頂。易混點(diǎn)二:can和may1. can和may均可用來(lái)征求意見或許可，意為“可以”，一般可互換使用。如：Can/ May I help you ? 我能幫助你嗎？2. can和may表示可能性時(shí)的區(qū)別：1)在肯定句中用might，may，must，不用can2)在疑問(wèn)句中表示推測(cè)用can，不用might，may，must3) 在否定句中用cant（不可能），不用may，must。如：She may be in the classroom . 她可能在教室里。Where can they be now? 他們現(xiàn)在可能在哪兒？ That cant be true. 那不可能是真的。易混點(diǎn)

32、三: may be和maybe 用法區(qū)別 常用位置may be may為情態(tài)動(dòng)詞，be為動(dòng)詞原形 句中，作謂語(yǔ)maybe 副詞，大概、也許，相當(dāng)于perhaps 句首，作狀語(yǔ)例如：He may be wrong , but Im not sure. 也許他錯(cuò)了，但我也不確定。易混點(diǎn)四：cant和mustnt1. cant根據(jù)其基本用法可譯為：（1）不會(huì)。如：I cant speak English .我不會(huì)說(shuō)英語(yǔ)。（2）不能。如：We cant do it now because its too dark. 天太黑了，我們現(xiàn)在干不了。（3）否定句中表示推測(cè)。“不可能”，如：The man cant be our teacher because he is