情態(tài)動詞的用法

1、情態(tài)動詞情態(tài)動詞的用法1定義:情態(tài)動詞是一種本身有一定的詞義，但要與動詞原形一起使用，給謂語動詞增添情態(tài)色彩，表示說話人對有關(guān)行為或事物的態(tài)度和看法，認為其可能、 應(yīng)該或必要等。情態(tài)動詞后面加動詞原形。分類:情態(tài)動詞有四類:1只做情態(tài)動詞：must,ca n( could),may(might),oughtto2可做情態(tài)動詞又可做實義動詞：n eed,dare3可做情態(tài)動詞又可做助動詞：shall(should),will(would)4具有情態(tài)動詞特征：have(had) to,used to位置:情態(tài)動詞在句中放在謂語動詞之前，謂語動詞前若有助動詞疑問句中，情態(tài)動詞則在主語之前。I can

2、 see you. Come here.我能看見你，過來吧。He must have been away.他一定走了。What can I do for you?我能幫你嗎？How dare you treat us like that！你怎能那樣對待我們！特點:情態(tài)動詞無人稱和數(shù)的變化,情態(tài)動詞后面跟的動詞需用原形，否定式構(gòu)成是在情態(tài)動詞后面加not。個別情態(tài)動詞有現(xiàn)在式和過去式兩種形式，過去式用來表達更加客氣，委婉的語氣 物動詞，故沒有被動語態(tài)。,時態(tài)性不強，可用于過去，現(xiàn)在或?qū)怼Ｇ閼B(tài)動詞屬非及He could be heresoon.他很快就來。We cant carry the he

3、avy box.我們搬不動那箱子。rm sorry I cant help you.對不起，我?guī)筒簧夏恪；局鷦釉~與情態(tài)助動詞最主要的區(qū)別之一是，基本助動詞本身沒有詞義，而情,則在助動詞之前情態(tài)動詞情態(tài)動詞的用法2態(tài)助動詞則有自己的詞義，能表示說話人對有關(guān)動作或狀態(tài)的看法，或表示主觀設(shè)想:What have you bee n doi ng si nee?（構(gòu)成完成進行體，本身無詞義）I am afraid I must be going.（定要）You may have read some account of the matter.（或許已經(jīng)）除此之外，情態(tài)助動詞還有如下詞法和句法特征：1

4、）除ought和used以外，其他情態(tài)動詞后面只能接不帶to的不定式。如果我們把ought to和used to看做是固定詞組的話，那么，所有情態(tài)動詞無一例外地只能接不帶to的不定式：We used to grow beautiful roses.I asked if he would come and repair my televisionset.2） 情態(tài)助動詞在限定動詞詞組總是位居第一：They need not have been punished so severely.3）情態(tài)助動詞用于第三人稱單數(shù)現(xiàn)在時的時候，沒有詞形變化，即其詞尾無s形式：She dare not say w

5、hat she thinks.4） 情態(tài)動詞沒有非限定形式，即沒有不定式和分詞形式，也沒有相應(yīng)的動名詞：Still, she neednt have run away.5）情態(tài)助動詞的時”的形式并不是時間區(qū)別的主要標志。在不少場合，情態(tài)助動詞的現(xiàn)在時和過去時形式都可以表示現(xiàn)在、過去或?qū)頃r間：Would you mind very much if I ask you to do something?She told him he ought not to have done it.6）情態(tài)助動詞之間是相互排斥的，即在一個限定動詞詞組中只能出現(xiàn)一個情態(tài)助動詞，但有時卻可以與have和be基本助動

6、詞連用：You should have washed the wound.Well, you should nt be readi ng a no vel.用法首先它是動詞，而且不同于行為動詞，行為動詞表示的是可以通過行為來表達的 動作（如寫，讀，跑），而情態(tài)動詞只是表達的一種想法（如能，也許，敢）。用法是：情態(tài)動詞+行為動詞原形例句：I can read this sentence in English.我能用英語讀這句話。情態(tài)動詞是一種本身有一定的詞義，表示說話人的情緒，態(tài)度或語氣的動詞，但不能單獨作謂語，只能和其他動詞原形構(gòu)成謂語。We can be there on time tomo

7、rrow.我們明天能按時去那兒。May I have your name?我能知道你的名字嗎？情態(tài)動詞情態(tài)動詞的用法3Shall we begin now?我們現(xiàn)在就開始嗎？You must obey the school rules.你必須遵守校規(guī)。情態(tài)動詞數(shù)量不多，但用途廣泛，主要有下列：can (could), may (might), must, need, ought to, dare (dared), shall (sho uld), will (would),have(to) ,had better.功能助動詞(auxiliary)主要有兩類：基本助動詞(primary auxi

8、liary)和情態(tài)助動詞(mod al auxiliary)。基本助動詞有三個：do, have和be;情態(tài)助動詞有十三個：may, might; can, could; will, would; shall, should; must, need, dare, used to, ought to.上述兩類助動詞的共同特征是，在協(xié)助主動詞構(gòu)成限定動詞詞組時，具有作用詞的功能：1)構(gòu)成否定式：He did nt go and n either did she.The meetingmight not start until 5 oclock.2)構(gòu)成疑問式或附加疑問式：Must you leav

9、e right now?You have bee n lear ningFrench for 5 years, have nt you?3)構(gòu)成修辭倒裝：Nowhere can he obtain any information about his sister.Hardly had he arrived when she started complaining.4)代替限定動詞詞組：A: Who can solve this crossword puzzle?B: Tom can.A: Shall I write to him?B: Yes, do.can和could的用法1.表示能力或客觀

10、可能性，還可以表示請求和允許。如：Can you finish this work tonight?Man cannot live without air.Can I go now?Yes, you can.注意：could也可表示請求，語氣委婉，主要用于疑問句，不可用于肯定句，答語應(yīng)用can(即could不能用于現(xiàn)在時態(tài)的簡略答語中)。如：Could I come to see you tomorrow?Yes, you can.(否定答語可用No, rm afraid not.)2can表示能力時，還可用be able to代替。如：情態(tài)動詞情態(tài)動詞的用法4ni not be able t

11、o come this after noon.2.表示驚異、懷疑、不相信的態(tài)度。(主要用在否定句、疑問句或驚嘆句中)Can this be true?How can you be so careless!This cannot be done by him.情態(tài)動詞情態(tài)動詞的用法53.“can( could) + have懷疑或不肯定。如：He cannot have beenCan he have got the book?表示“無論怎樣 、 也不過分,越 、 越好 may禾口might的用法1.表示許可。表示請求、允許時，might比may的語氣更委婉一些，否定回答時（口語中常用）no ,

12、 you cant . or , yes, please用must nt表示不可以”禁止”阻止之意（具有強烈禁止的意思）如：You may drive the car.Might I use your pen?No, you must nt.用May I .征詢對方許可在文體上比較正式，在口氣上比較客氣。在日常口語 中，用Can I .征詢對方意見在現(xiàn)代口語中更為常見。2.用于祈使句中表示祝愿。如：May you succeed!3.表示推測、可能（疑問句不能用于此意）。He may be very busy now.4.“may（might） + have +過去分詞表示對過去發(fā)生的行為的推

13、測。如:He may not have finished the work.must禾口have to的用法（must表示主觀多一些而have to則表示客觀多一些）如:You must come in time.回答must引出的問句時，如果是否定的回答，不能用must nt,而要用need nt或dont have to。Must we hand in our exercise books today?Yes, you must. （No, you donthave to.）2.“must be +表語的結(jié)構(gòu)表示推測，它的否定或疑問式用can代替must。This must be your

14、 pen.3.“must + have +過去分詞的結(jié)構(gòu)常用在肯定句中，表示對過去發(fā)生的行為+過去分詞”的疑問或否定形式表示對過去發(fā)生的行為to that town.4.用在疑問句及否定句中,表示驚訝，不相信等5. canno t、 tooe noughi.表示必須、必要。情態(tài)動詞情態(tài)動詞的用法6的推測。它的否定或疑問式用can代替must。He must have been to Shanghai.4.have to的含義與must相似，兩者往往可以互換使用，但have to有各種形式，隨have的變化而定。must與have to有下列幾點不同：must表示的是說話人的主觀看法，而have

15、 to則往往強調(diào)客觀需要。如：The play is not interesting.I really must go now.I had to work when I was your age.2must般只表現(xiàn)在，have則有更多的時態(tài)形式。3二者的否定意義不大相同。如：You must nt go.你可不要去。You dont have to go.你不必去。4詢問對方的意愿時應(yīng)用must。如：Must I clean all the room?注意：have to也可拼做have got to。dare禾口need的用法1.need表示需要或必須”作情態(tài)動詞時，僅用于否定句或疑問句中，

16、在肯定句中一般用must, have to, ought to,或should代替。如：You needn t come so early.Need I finish the work today?Yes, you must.注意：need nt +不定式的完成式表示本來不必做某事而實際上做了某事”如:You neednt have waited for me.2.Dare作情態(tài)動詞時，主要用于疑問句、否定句和條件從句中，一般不用在肯定句中。如：How dare you say rm unfair.He dare nt speak En glish before such a crowd, d

17、are he?3.Dare和need常用作實義動詞，有時態(tài)、人稱和數(shù)的變化，所不同的是，作實義動詞時，在肯定句中，dare后面通常接帶to的不定式，在否定和疑問句中，dare后面可接帶to或不帶to的不定式。如：I dare to swim across this river.He does not dare (to) answer.Dont you dare (to) touch it!I wonderedhe dare (to) say that.He needs to finish it this evening.情態(tài)動詞情態(tài)動詞的用法7shall和should的用法一.Shall的用法

18、：1.Shall用于第一人稱，表示征求對方的意愿。如：What shall we do this evening?2.Shall用于第一、第三人稱疑問句中，表示說話人征求對方的意見或向?qū)Ψ秸埵?。如：Shall we begi n our less on?When shall he be able to leave the hospital?3.Shall用于第二、第三人稱，表示說話人給對方命令、警告、允諾或威脅。如:You shall fail if you dont work harder.（警告）He shall have the book when I finish reading.（允

19、諾）He shall be punished.（威脅）二.Should的用法：1.Should表示勸告、建議、命令，其同義詞是ought to;在疑問句中，通常用should代替ought to。如：You should go to class right away.Should I open the window?Should的含義較多，用法較活，現(xiàn)介紹三種其特殊用法。請看下面的句子：I shouldthink it would bebetter to try it again.我倒是認為最好再試試。You aremistake n,1 shouldsay.依我看，你是搞錯了。I shoul

20、dadvise you not todo that.我倒是勸你別這樣做。This issomething I shouldhaveliked to ask you.這是我本來想冋你的。從以上例句可以看出：情態(tài)動詞should用于第一人稱時可以表示說話人的一種謙遜、客氣、委婉的語氣。Should還可以用在if引導(dǎo)的條件從句，表示一件事聽起來可能性很小，但也不 是完全沒有可能。相當(dāng)于 萬一的意思。從句謂語由should加動詞原形構(gòu)成，主句謂語卻不一定用虛擬語氣。如：5Ask her to ring me up if you should see her.你萬一見至U她，請讓她給我打個電話。6If

21、you should change your mind, please let us know.萬一你改變主 意，請通知我們。7Should I (If I should) be free tomorrow I will come.萬一我明天有時 間，我就來。此外，Why(or How) + should結(jié)構(gòu)表示說話人對某事不能理解，感到意外、驚 異等意思。意為竟會”女口：8Why should you be so late today?你幾天怎么來得這么晚？9一Where is Betty living?貝蒂住在哪里？情態(tài)動詞情態(tài)動詞的用法8How should I know? 我怎么會知道

22、呢？10I do nt know why you should thi nk that I did it.我真不知道你憑什么 認為這件事是我干的。2.“should + have +過去分詞結(jié)構(gòu)一般表示義務(wù)，表示應(yīng)該做到而實際上沒有做到，并包含一種埋怨、責(zé)備的口氣。如：She should have finished it.情態(tài)動詞情態(tài)動詞的用法9should have helped her, but I never could.You should have started earlier.will禾口would的用法1.表示請求、建議等，would比will委婉客氣。如：Would you

23、 pass me the book?2.表示意志、愿望和決心。如：I will never do that again.They asked if we would do that again.The door wont open3.用will be和“will(would) + have +過去分詞的結(jié)構(gòu)表示推測，主要用于第二、三人稱。前者表示對目前情況的推測，后者表示對已經(jīng)完成的動作或事態(tài)的推測。如：This will be the book you want.He will have arrived by now.The guests would have arrived by that

24、 time.I thought you would have finishedthis by now.4. Would可表示過去反復(fù)發(fā)生的動作或某種傾向。Would表過去習(xí)慣時比usedto正式，并沒有 現(xiàn)已無此習(xí)慣”的含義。如:The wound would not heal.During the vacation he would visit me every week.5.表料想或猜想。如：It would be about ten when he left home.What would she be doing there?I thought he would have told y

25、ou all about it.1.Ought to表示應(yīng)該。如：You ought to take care of him.2.表示推測。注意與must表示推測時的區(qū)別：He must be at home by now.（斷定他已至U家）He ought to be home by now.（不十分肯定）This is where the oil must be.（比較直率）This is where the oil ought to be.（比較含蓄）3.“ought to + have +過去分詞表示過去應(yīng)做某事而實際未做。如：You ought to have asked him （

26、but you did nt）.這時，ought to和should可以互相換用。注意：在美國英語中，ought to用于否定句和疑問句時，to可以省略。如:ought情態(tài)動詞情態(tài)動詞的用法10Ought you smoke so much?You ought ntsmoke so much.ought和should的區(qū)別：l.ought語氣略強。2.should較常用。3.ought在美國英語中用的很少，而should卻相當(dāng)常用。4.ought屬正式用語。used to，had better，would rather的用法1. Used to表示過去的習(xí)慣動作或狀態(tài)，現(xiàn)在已不存在，在間接引語

27、中，其形 式可不變。如：He told us he used to play football when he was young.在疑問句、否定句、否定疑問句或強調(diào)句中，可有兩種形式：疑問句Did you use to go to the same school as your brother?Used you to go to the same school as your brother?否定句I used nt to go there.I did nt use to go there.Used nt亦可拼作use nt，但發(fā)音皆為ju:s nt。否定疑問句Usent you to be

28、 interestedin the theatre?Didnt you use to be interested in the theatre?強調(diào)句I certainlyused to smoke, but it was a long time ago.I certainlydid use to smoke, but it was a long time ago.其反意疑問句或簡略回答中，也有兩種形式：She used to be very fat, did nt she?(口語+常用)/ use(d) nt she?(正 式+過時)Did you use to play chess? Ye

29、s, I did.Used you to get up early in the morning?Yes, I did. (Yes, I used to.)2.Had better意為最好”后接不帶to的不定式。如：We had better go now.Yes, we had (wed better / we had better).Hadnt we better stop now? (Had we better not stop now?)I think rd better be going.(用于進行時態(tài)，表最好立即 ”You had better have done that.(用于

30、完成時態(tài)，表未完成動作)情態(tài)動詞情態(tài)動詞的用法11注：had best與had better同意，但較少用。You had better用于同輩或小輩，對長輩不可用。3.Would rather意為寧愿”表選擇，后接不帶to的不定式。如：rd rather not say anything.Would you rather work on a farm?Would nt you rather stay here?No, I would not. rd rather go there.由于would rather表選擇，因而后可接than。如:I wouldratherwork on a far

31、mthanin afactory.I wouldratherwatchTV thango tosee the film.I wouldratherlosea dozen cherrytreestha n that youshouldtell me one lie.Id ratheryou did nttalk aboutthisto anyone.（句中的d rather不是情態(tài)動詞，would在此是表愿望的實義動詞)can (could), may (might),用法:can (could)表示說話人能，可以,同意 準許，以及客觀條件許可,could為can的過去式。Can you pas

32、s me the books?你能給我遞一下書嗎？Could you help me, please?請問，你能幫助我嗎？What can you do?你能干點什么呢？Can you be sure?你有把握嗎？can和could只能用于現(xiàn)在式和過去式兩種時態(tài)，將來時態(tài)用be able to來表示。He could help us at all.他完全可以幫助我們。With the teachers help,I shall be able to speak English correctly.由于老師的幫助，我將能準確地講英語。may (might)可以，表示說話人同意，許可或請求對方許可

33、。You may take the book home.你可以把書帶回家去May I come in?我可以進來嗎？情態(tài)動詞情態(tài)動詞的用法12May I use your dicti on ary?我可以用你的詞典嗎？You may put on more clothes.你可以多穿點衣服.He said he might lend us some money.他說他可以借給我們一些錢。may否定式為may not,縮寫形式是maynt.might是may的過去式,有兩種用法,一種表示過去式，一種表示虛擬語氣,使語氣更加委婉，客氣或?qū)赡苄缘膽岩?。He told me he might be

34、here on time.他說他能按時間來。Might I borrow some money now.我可以借點錢嗎？He might be alive.他可能還活著。must, need, ought to, dare （dared）用法Must必須，應(yīng)該，一定,準是，表示說話人認為有必要做某事，命令，要求別人做某事以及對事物的推測。must用來指一般現(xiàn)在時和一般將來時，過去式可用have to的過去式代替。I must finish my work today.我今天必須完成我的工作。You must nt work all the time.你不能老是工作。Must I return

35、the book tomorrow?我必須明天還書嗎？After such a long walk, you must be tired.走了這么長的路，你一定困了。He must be the man I am looking for.他一定是我要找的人。He had to go because of somebodyscalling him that day.那天他要走是因為有人叫他。must + have +過去分詞，表示現(xiàn)在對過去事物的推測。He must have told my parents about it.他一定把這件事情告訴我父母親了。He must have receiv

36、ed my letter now.他現(xiàn)在一定收到我的信了。Its six oclock already, we must have been late again.已經(jīng)六點鐘了，我們一定又遲到了。must和have to的區(qū)別：must表示說話人的主觀思想，have to表示客觀需要。You must do it now.情態(tài)動詞情態(tài)動詞的用法13你必需現(xiàn)在就干。（說話人認為必須現(xiàn)在干）I have to go now.我得走了。（客觀條件必須現(xiàn)在走）n eed需要多用在否定式或疑問句中Need I attend the meeting tomorrow?我需要明天參加會議嗎？You need

37、 not hand in the paper this week.這一周你不必交論文。need是一個情態(tài)動詞,他的用法完全和其他情態(tài)動詞一樣,但need還可當(dāng)作實義動詞使用，這時need就象其他動詞一樣，有第三人稱，單復(fù)數(shù)，后面加帶to的 動詞等特性。I need a bike to go to school.我上學(xué)需要一輛自行車。Do you n eed a diet ion ary?你需要詞典嗎？She needs a necklace.她需要一條項鏈。n eed nt + have +過去分詞表示過去做了沒必要做的事情。You neednt have taken it seriously.這件事情你不必太認真。dare敢 多用在否定或疑問句中。The little girl dare not speak in public.小女孩不敢在公眾面前說話。Dare you catch the little cat?你敢抓小貓嗎？dare除用作情態(tài)動詞外，更多的是當(dāng)實義動詞使用，用法同實義動詞一樣，要考慮人稱，單復(fù)數(shù)，時態(tài)等。Do you dare to walk in the dark?你敢黑夜走路嗎？He does nt dare to tell the teacher w