初中英語(yǔ)情態(tài)動(dòng)詞講解

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，需要及其他詞語(yǔ)一起構(gòu)成句子的謂語(yǔ)，另外情態(tài)動(dòng)詞沒(méi)有人稱和數(shù)的變化，情態(tài)動(dòng)詞后必須跟動(dòng)詞原形。考點(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。如：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。如：You can use my

2、dictionary. 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”。如：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。【例題】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.【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 2. could的用法：（1）.can的過(guò)去式，意為“能、會(huì)”，表示過(guò)去的能力。如：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(méi)有過(guò)去式的意思。如:Could you do me 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）3. may的用法：（1）.表示請(qǐng)求、許可，比can正式，

4、如：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。【例題】_ 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?，意為“可能，或許”，一般用于肯定句中。如：It may rain tomorrow .明天可能會(huì)下雨。She may be at home.她可能在家呢. (3) .may的過(guò)去式為might，表示推測(cè)時(shí)。可能性低于may。如：He

5、is away from school. He might be sick.他離開(kāi)學(xué)校了，可能是他生病了。 (4) . 表示希望、祈求、祝愿，常可譯為“祝愿”。通常是用may +主+V例如：May 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”。如：You must stay here until I come back.在我回來(lái)之前你必須呆在這兒。Must I hand in my homework right now?我必須現(xiàn)

6、在交作業(yè)嗎？（2）對(duì)must引導(dǎo)的疑問(wèn)句，肯定回答為must，否定回答或dont have to .如：Must I finish my homework?我現(xiàn)在必須完成作業(yè)嗎 (4)must表示有把握的推測(cè)，用于肯定句。如: The light is on, so he must 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。如：She must have seen the film before?(注意反意疑問(wèn)句的后半部分)You must have met uncle Wang i

7、n the shop (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，意為“沒(méi)有必要，不必”。用need提問(wèn)時(shí)，肯定回答dont have to。如：Need I stay here any longer? 我還有必要留在這兒?jiǎn)?？Yes, you must .是的。No. you /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。如：I need to do it right now.我需要馬上做這件事。He needs to learn more

8、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及need to be done這種情況下應(yīng)注意兩點(diǎn)：.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。例如：. 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。7. shall的用法：shall表示征求對(duì)方意見(jiàn)（多用于第一、三人稱），如：

9、Shall 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(jiàn)。(1).用“Let's do.”來(lái)提出建議。如：Let's 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。如：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.?

10、”實(shí)際上是“Why don't you/we.?”的簡(jiǎn)略形式。如：Why not meet at the school gate at eight? Why don't 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。如：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?Let

11、's go for a swim，shall we?What about/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。如：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)。如：You should have

12、finished your homework.你應(yīng)該已經(jīng)完成作業(yè)了。（事實(shí)上你沒(méi)有完成。）9. will的用法：will表示意愿、意志、打算，可用于多種人稱。如：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）例如：There are many students in our school.

13、There will be many students in our school. There will be a sports meeting next week.一定不能說(shuō)：There will have a sports meeting next week.2、will及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，如：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

14、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 ill. 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(méi)有這個(gè)意思，如：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,如：If any beasts comes at you, I'll stay with you and hel

15、p you.10. had better的用法：had better意為“最好”，沒(méi)有人稱的變化，后面接不帶to的不定式，其否定形式為：had better not。如：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(shū)給他。考點(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 cant.2.對(duì)must引出的疑問(wèn)句，回答方式為：Yes, must.

16、 No,dont have to.3.could在疑問(wèn)句中，表示委婉的語(yǔ)氣，此時(shí)could沒(méi)有過(guò)去式的意思。如:Could you do me a 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(jiàn)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 ri

17、ght/ OK/ With pleasure.Certainly. (No, thank you .)Yes, please.【例題】Would you do me ass on my thanks to Lily?_.A.Thats right B.With pleasure D.No trouble【解析】A.意為“對(duì)了”，B.意為“樂(lè)意效勞”, C.意為“沒(méi)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)”，如：I cant play basketball.我不會(huì)打籃球。（2）當(dāng)句子表推測(cè)時(shí)，用cant表達(dá)不可能，如：He can

18、t 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。如：May I come in ? 我可以進(jìn)來(lái)嗎？No, . / 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迫不及待地要做如：She cant help crying.她不禁大哭起來(lái)。The children cant wait to open the box.孩子們迫不及待地想打開(kāi)盒子。2. may的否定式為may

19、 not，譯成“可能不”，如：He may not be at home.他也許不在家?？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。She should 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(shù)木。Many of the stars can not be seen because they are far away from

20、 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。如：That man cant be her husbandshe 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。如：He must be in his office now.Mr Li must be working now，for the lights in his office are s

21、till 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。如：The man may be the headmaster.Where is Mr Li?He might be 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。如：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)。如：It is

22、already 10 oclock now they should be there.【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。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(jiàn)到他。He has be

23、en able to drive.他已經(jīng)會(huì)開(kāi)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(jiàn)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，

24、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)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1. 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)?！安豢赡堋?，如：The man cant be our teacher because he is much younger than our teacher.那個(gè)人不可能是咱們老師，他年輕得多。易混點(diǎn)五：must和have to1.must側(cè)重于個(gè)人意志和主觀上的必要。have to側(cè)重于客觀上的必要，可用于現(xiàn)在時(shí)、過(guò)去時(shí)和將來(lái)時(shí)。如：I kno