情態(tài)動詞語法講解（課堂PPT）

1、12情態(tài)動詞（modal verbs)： 表示說話人的語氣或情態(tài)，如請求、命令、愿望、能力以及可能性等。英語的情態(tài)動詞有：3 can/could may/might must shall/should will/would need have to 能夠可能必須應(yīng)該意愿敢需要不得不+ 動詞原形45一、情態(tài)意義表示法一、情態(tài)意義表示法1.表示表示“能力能力”和和“可能可能” a)表示表示“能力能力”，可用，可用can, could, be able to can既能表示現(xiàn)在的能力，也表示將來的既能表示現(xiàn)在的能力，也表示將來的能力。能力。Eg.Look! I can do it. I cant d

2、o it now, but I can do it later.6現(xiàn)在“能力”：can, be able to As I have got enough money, I can/am able to help her.Can: 某樁具體事情：eg.I can climb this cliff. 泛指一般的“能力”： He can drive a car. She cant play the piano.7將來“能力”：通常 will/shall be able to Ill be able to speak German in another two months具體某事：can Can y

3、ou go and see him tomorrow morning? If I can, I will do it.8過去“能力”: could, was/were able to 肯定句：Could：一般能力 She could play the piano when she was only six. was/were able to(及managed to)：具體事件 He was able to translate the article without a dictionary.9 I talked a long time, and in the end managed to ma

4、ke her believe me.在否定句中，could既可以表示過去一般能力，也可表示過去某具體事情的能力. I couldnt/wasnt able to play the piano when I was at school.10b)表示“可能”，可用may, might, can, could may/might： 既可以表示現(xiàn)在的可能，也可表示將來的可能，might在口氣上比may更委婉 現(xiàn)在：It may/might be true. 將來：He may/might leave tomorrow.2.在疑問句中，用can，不用may。 Can they have missed t

5、he bus?1.Yes, they may have.11may not重音落在助動詞上，表示“不可能”，重音落在否定詞上，表示“不許可” , 比較：He may not go tomorrow.He may not go tomorrow.所以在書面語中，表示“不可能”常用cant12can/could表示現(xiàn)在的可能，口氣上could比較委婉vThats not mine. Whose can it be?vIt could be Johns.can常用于否定句和疑問句，而could不受此限。vIf you dont have a guide, you could lose your wa

6、y.vIt cant/couldnt be true.vCan/could the news be true?13在肯定陳述句中，may與can的比較：Can指邏輯上的可能性，may指事實上的可能性 The road can be blocked.(按邏輯可能會堵，)The road may be blocked.(可能現(xiàn)在正堵著，事實上) Mr Reed is in poor health. He can be ill at any time. Mr Reed looks pale. He may be ill.14“may/might +have done/have been doing”

7、,“can/could +have done”表示過去的可能。vHe may/might have missed the train.vShe may/might have been expressing her true feelings at that moment.vShe cant/couldnt have missed the train.“might/could +have done ”可以表示本來可能發(fā)生但沒有發(fā)生的，或者本來可能完成卻沒有完成的動作，vYou might have finished the work last week.vI could have passed

8、the examination, but I failed.15a)請求對方“許可”可用can, could, may, might. may/might較正式，could/might較委婉表示給予“許可”通常用can/may,而不用could/might Could I use your phone? Yes, of course you can. Might I trouble you for a light? You may indeed.16b)表示“不許”可用may not或者cannotCan I go out for a moment?No, you cant. May I us

9、e your car for a few days?No, you may not. may not也可表示根據(jù)一般規(guī)定的“不許可”，而不是說話人不許可Borrowers may not take out of the library more than two books at a time. may not表示“不許可”的過去式不是might not He may not go.(=I dont permit him to go.)He might not go.(=Possibly he will not go.)過去的不許可：He was not allowed to go.17a)表

10、示“義務(wù)”，可用should, ought to, must. 表示要求，命令時，語氣由ought to、 should、must漸強Should/ought to表示“應(yīng)該”，帶有敦促，勸說之意，可交替使用，前者語氣更強。You should/ought to drink less.Should/ought to +have done:本應(yīng)該You should/ought to have asked my permission first.Must表示敦促或命令，必須。I really must stop smoking.18表示將來的“必須”，常用have to的一定形式（will/sh

11、all have to) 比較：We must do it again.(表示現(xiàn)在)Well have to do it again.(表示將來)表示過去的“必須”，常用had toI had to leave at six yesterday.must有兩種否定形式:第一個是must not,表示“不許”、“禁止”,相應(yīng)的半助動詞是be to的否定形式be not toYou mustnt talk like that.You are not to talk like that.(不許你如此講話。)19第二個否定形式是neednt,表示不必。與neednt相當(dāng)?shù)膭釉~形式是dont need

12、to/dont have to/havent got toA: Must you leave soon?B: No, I neednt/dont need to/dont have to/havent got to.必須：must與have tomust側(cè)重于說話人的主觀意志 have to側(cè)重客觀需要 He must say it in English. (I want him to do so.)He have to say it in English. (He doesnt know Chinese.) 在特定語境中，用will也可表示“義務(wù)”，常用于第二人稱主語，這實際上是強化的祈使句

13、。You will wait outside the gate.Brian! You will close the door.20b)表示“必然”，可用should，ought to和must(一般用于陳述句)，其中must口氣最為肯定。都指說話人根據(jù)一定情況做出推測或判斷.She should be here in a minuteThese young trees ought to provide shade in ten years .All men must die.ought to(表示“推測”）的否定形式是oughtnt toYou oughtnt to have any diff

14、iculty getting the tickets.21如果是推測過去的事態(tài)，則用must +have doneYou must have left your handbag in the theatre.表示推測的must的否定形式是cant不是must notIf Fred didnt leave home before five, he cant be there yet.22a)表示“預(yù)見”，即表示“單純將來”，可用will/shall+不定式，shall用于第一人稱，will用于第二、三人稱?，F(xiàn)在一般will可用于一切人稱表“將來”I will be a different per

15、son when I live in England.You will be hearing from me.She will probably last longer than you will.It will rain tomorrow.非正式語體中，will常用語第一人稱主語表將來，常用will、shall的縮寫ll，模糊了其界限。Ill come in after church and give you a hand.23b)表示“推測”，除用should, ought to,和must外，還可用will/would（語氣僅次于must）。They should/ought to be

16、 home by now.(他們現(xiàn)在該到家了)They would be home by now.(他們現(xiàn)在大概到家了)They will be home by now.（我估計他們現(xiàn)在一定到家了）They must be home by now.（他們現(xiàn)在一定到家了）24will/would表示“推測”可有三種情況 1）對特定事態(tài)的推測 A: Whos that man over there? B: That will be George, no doubt. C: That would be George, I except.2）對某些習(xí)慣性事態(tài)的推測，will指現(xiàn)在習(xí) 慣，would指過

17、去習(xí)慣vHe will work all day without a rest.vBefore his retirement he would catch the early bus every morning.3）對某些不受時限的客觀過程的推測，只用will,表示現(xiàn)在時間，可與一般現(xiàn)在時的類似用法交替使用。 Pigs will eat anything.=Pigs eat anything.255表示“意愿”、“意圖”和“決心”，a)表示意愿都可用will, would, shall。 will用于一切人稱的主語,可縮寫，will相當(dāng)于be willing to ,I will lend y

18、ou the money if you need it.My sister will help you with the luggage.You can help me if you will.Will用于第二，三人稱的疑問句，是詢問別人是否愿意做某事，請求Will you please open the door for me?此時，will=would you, would you please, would you be good enough to ,would you like to, would you be so kind as to表示接受請求時，用will不用wouldWou

19、ld you lend me your pen a minute?Certainly, I will.26表示不愿意，用will not/wontI will not do anything solely for money.表示過去的意愿或者不愿意用would, wouldnt,間接引語I asked him if he would help me with my writing.shall一般用于第二、三人稱主語，表示說話人的意愿,而不是句子主語的意愿，在疑問句中表示征詢聽話人的意愿You shall stay with us as long as you like=Im willing

20、to let you stay with us as long asHe shall be praised if he works hard for the people=Ill see that he is praisedShall you take a holiday this summer?27b)表示意圖，同上a)用法一致。c)表示決心，同上shall表示“決心”時，否定形式為shall not /shant，表示說話人禁止、威脅No one shall stop me.28 should可在某些語境中表示惋惜、憂慮、歡欣、驚訝等感情色彩。例如在某些that-分句，慣用的疑問句和感嘆句

21、中。 How should I know? That he should dare to attack me!還可用在某些語境中并不表示具體的情態(tài)意義。例如在be-型虛擬式中或狀語分句中。 I insisted that he go/should go with me. They got warmly dressed for fear that they should catch cold. 此外，should還可以和say，think搭配表示婉轉(zhuǎn)口氣。 I should say he is just the right man for the job.29b) would可用于委婉的簡述，客

22、氣的請求,委婉的建議I dont think he would be so careless.(委婉的陳述)Would you like to stay here for the night?(客氣的請求)Wouldnt it be better for us to start off a little earlier tomorrow morning？(委婉的建議)30c)作為情態(tài)動詞表示“膽敢”，dare通常只用于否定陳述句和疑問句,I dare not go there.多用于現(xiàn)在時形式，但它既可以指現(xiàn)在時間，The presidet was so hot-tempered that n

23、o one dare tell him the bad news.也可指過去時間。否定形式為darent。 Tom wanted to come, but he darent. dare用作主動詞，通常用于否定句和疑問句。 He does not dare (to) answer. dare的過去式dared通常只用于文學(xué)語言等正式語體，也還是用于否定意義。Nobody dared lift their eyes from the ground.31d) need表示“必須，需要”，做情態(tài)助動詞，只用于否定句和疑問句，He neednt worry about it.作情態(tài)助動詞，答語肯定，m

24、ust；否定，neednt Need we work late today? No, but we must tomorrow. Need I tell Elizabeth at once? No, you neednt tell he just yet. 詢問對方是否需要，必須做某事，可用need，也可用must, 否定用neednt或dont have to A: Must I see a doctor at once? B: No, you neednt/dont have to see a doctor for the time being.32Neednt +have done，表示過去本來不必做的事卻做了You neednt have bought that house.Didnt need to 與neednt have +-ed