最全情態(tài)動(dòng)詞的用法

1、情態(tài)動(dòng)詞的用法一 can 和 could情態(tài)動(dòng)詞用法例子補(bǔ)充說明表示能力在肯定句中，表示客觀可能性，并不涉及具體某事會(huì)發(fā)生，常用來說明人或事物的特征。 要表達(dá)具體某事實(shí)際發(fā)生的可能can/could性時(shí)，不用can，需用could ， may， might 。表示請(qǐng)求和允許。 表示請(qǐng)求，口語中常用 could 代替 can，使語氣更委婉。表示對(duì)現(xiàn)在的動(dòng)作或狀態(tài)進(jìn)行主觀的猜測(cè)， 主要用在否定句和疑問句中。表示驚異、 懷疑、不相信等態(tài)度，主要用在否定句、疑問句和感嘆句中。特別提示：1I can speak fluent English now, but I couldn t last year.1

2、. I may stay at home this weekend.（實(shí)際可能性）2. Peter might come to join us.(實(shí)際可能性 )3. It will be sunny in the daytime ,but it could rain tonight.(實(shí)際可能性 )1Can we turn the air conditioner on?.2. I wonder if I could just ask you to sign this.1It canbet easy caring for a man and a child who are not your ow

3、n.2Can the man over there be our head master?1Can this be an excuse for not giving them help?2This can t be true.3How can you be so crazy!Can 表現(xiàn)在能力； Could 表示過去能力 .可用 be able to 代替；was/were able to 表示成功做了某事1. can 用于否定和疑問句 (could不限 )2. can (be)表示有時(shí)候會(huì)（常與 sometimes, at times連用）1. 請(qǐng)求用 could 語氣委婉2. 允許不用 c

4、ould.（ 1）could 用來表示請(qǐng)求時(shí)，語氣委婉，主要用于疑問句，不能用于肯定句，回答應(yīng)該用can（即： could 不能用于現(xiàn)在時(shí)態(tài)的簡(jiǎn)略答語中） 。如： Could I use your dictionary? Yes, you can.(否定回答可用： No, I m afraid not.)(2)can 和 be able to 區(qū)分can(could) 和 be able to 都可以表示能力，意思上沒有區(qū)別。但can 只有現(xiàn)在式和過去式，而be able to 則有更多的形式。如：I ve always wanted to able to speak fluent Engli

5、sh.Those bags look really heavy, are you sure you ll be able to carry them on your own?但是，表示在過去某時(shí)的某一場(chǎng)合經(jīng)過一番努力，終于做成了某事，通常不用could，而用 was/were able to 來表示。這時(shí)， was/were able to 相當(dāng)于 managed to do 或 succeed in doing。如：After the accident it was a long time before she was able to walk again.The fire was very

6、 big, but most people were able to escape from the building.(3) 慣用形式“ cannot too ”表示“無論怎么 也不（過分） ”。如：You cannot be too careful. 你越小心越好。慣用形式“ cannot but+ 不定式（不帶to）”表示“不得不，只好”。如：I cannot but admire her determination. 我不得不欽佩你的決心。二 may 和 might情態(tài)動(dòng)詞用法表示允許、許可。否定回答一般用mustnot/mustn t, 表示 “禁止、 阻止” 之意，但也可以用had

7、 better not (最好別 )或 may not （不可以），語氣較為委婉。在表示請(qǐng)求、 允許時(shí)， might 比 may 語氣更委婉些。用 May I 征詢對(duì)方許可在文體上比較正式，在口氣上比較客氣，在日常用語中，用Can I征詢對(duì)方意見更為常見。may/might表示可能性的推測(cè)，通常用在肯定句和否定句中，含有“或許”“大概”“可能”之意；用might 代替 may 時(shí)，則語氣顯得更加不肯定。may用于祈使句表示祝愿例子1 May I come in and wait?2 May I smoke here? No, you mustn 或t( No, you d better not

8、.)1 Might I borrow your pen?2 I wonder if I might speak to your son.1 It may rain this afternoon.2 I suppose he might have missed the train.1 May you succeed ！補(bǔ)充說明1. 請(qǐng)求用 might 語氣更委婉。2. 允許時(shí)用 may，表示“可以”（表示允許時(shí)不用might）。常用于肯定句（ might 可能最小）慣用句式：“may well+ 動(dòng)詞原形”，意為“完全能，很可能”，相當(dāng)于 to be very likely to“may as

9、well 或 might(just)as well+動(dòng)詞原形”意為“最好，滿可以，倒不如”，相當(dāng)于 “ had better或 thereis noreason to do anything else.1 There is nothing to do, so I may as well go to bed.2 You may as well tell us now, we ll find out sooner or later.3 I suppose we might as well gohome.二 must 和 have to情態(tài)動(dòng)用法詞表示“必須，應(yīng)該”之意，語氣比Mustshould，

10、ought to 強(qiáng)烈。其否定形式mustnt表示“不準(zhǔn)，不應(yīng)該，禁止”例子1 You must come to school on time.2 You mustnt drive so fast in the street.補(bǔ)充說明1. must 多表主觀、現(xiàn)在 /將來義務(wù) ; have to 多表客觀、過去義務(wù)等意在回答帶有 must 的問句時(shí)，否定回答常用 neednt或 donthave to，表示“不必” ，而不用 mustnt 表示有把握的推測(cè)，意為“一定、準(zhǔn)是”have to“必須，不得不” ，意義與 must 相近。但 must 表示的是說話人的主觀看法，而 have to 則

11、往往強(qiáng)調(diào)客觀需要。must 只有一種形式， 即現(xiàn)在式與過去式都是一種形式，而 have to 則涉及各種人稱、 時(shí)態(tài)等方面的變化形式。兩者的否定意義不同， mustnt表示“禁止，不許” ，donthave to 表示不必。3 We mustntwaste any more time.1 Must I come back before ten?Yes，you must.(No, you needn t)1 It must be my mother.2 You must be hungry after a walk.3 There must be a hole in the wall.1 The

12、 film is not interesting. I really must go now.2 I have to go now, because my mother is in hospital.1 I had to work hard when I was your age.2In order to take the exam, we ll have to finish the whole book by the end of this month.1 You mustntgo there.2 You donthave to go there.2. mustn't 表 "

13、; 禁止 " ；否定用needn't / don't have to只用肯定句。在否定句 /疑問句中用 can/could3四 shall 和 should情態(tài)動(dòng)用法詞例句補(bǔ)充說明shall用于第一、二、三人稱構(gòu)成的疑問句，表示征求對(duì)方意見或請(qǐng)求指示用于第二、三人稱陳述句中，表示說話人給對(duì)方的命令、警告、允諾或威脅。should表示勸告或建議，意為“應(yīng)該”表示推測(cè)，用在肯定句中，對(duì)現(xiàn)在的情況或可能發(fā)生的事的主觀推測(cè)或期待。 意為“想必，大概，或許”1 Shall I open the window?2 Shall we say 6 o clock, then?3 Wh

14、at shall I get for dinner?1 Dont worry, you shall gettheanswer this afternoon.( 允諾 )2 He shall be sorry for it one day,Itell you. （警告）3 You shall do as I say. (命令 )4 If you children dont do as Itellyou, you shall not go to the party.(威脅 )1 What should I do?2 Should I trust him?3 You should read his

15、new book.1 It should be a nice day tomorrow.2 Try phoning Robert, he should be home now.3 He should be around sixty years表規(guī)章、法令、預(yù)言：“必須”用 于 所 有 人 稱 Every competitor shall wear a number肯定的語氣沒有 must 用于推測(cè)時(shí)強(qiáng) This pen ought to /should be yours.還可以用在 if 引導(dǎo)的條件句中，表示一件事聽起來可能性很小，但也不是完全不可能， 相當(dāng)于“萬一” 的意思。 從句謂語用 s

16、hould+ 動(dòng)詞原形構(gòu)成，主句都一定用虛擬語氣用于疑問句或感嘆句中，表示意外、驚異的情緒，意為“竟會(huì)”，與 why ， what， how， who 連用，如果是疑問句，則不需要回答。old.1 AskTom to ringme up ifyoushould see him.( 你萬一見到湯姆，請(qǐng)讓他給我打個(gè)電話)2 Should Ibe free tomorrow,I llcome. ( 萬一我明天有時(shí)間，我就過來 )3 If things should change suddenly, please let me know. ( 萬一情況突變，請(qǐng)通知我 )1 Why should any

17、one want to marryTony?2 Dont askme.HowshouldIknow?五 will 和 would情態(tài)動(dòng)詞用法例句補(bǔ)充說明will/would用于表示意志或意愿。 will 指現(xiàn)在， would 指過去。表示請(qǐng)求、 建議等， 用 would 比用 will 委婉、客氣。表示習(xí)慣或傾向，意為“總是，慣于”。will 至現(xiàn)在，would指過去。表示推測(cè)，意為“很可能，大 概 ”。 will表 示 推 測(cè) 比should 把握大，比 must 把握小。表示功能，意為“能，行” 。慣用形式： will do/would do 表示“解決問題” 、“就行”。用于否定句中，

18、意為“不肯”、“不樂意”1 He is the man who will go his ownway. ( 他是個(gè)自行其是的人。)2 They said they wouldmeet us at10:30 at the station.1 Willyou please take a message forhim?2 Would you please tell me your telephone number?1 Fish will die without water.2 People willtalk.( 人們總會(huì)說閑話。 )3 When we worked in the same offic

19、e, we would often have coffee together.1 These things will happen.2 That will be the messenger ringing.3 It would be about ten o clock when he left home.1 That will be all right.2 Either pen will do.3 It would not do to work too late. （工作太晚不行。）1 I won tlisten to your nonsense.2 No matter what I said

20、, he wouldn t listen to me.Would 此時(shí)為 will 過去式，無意義差別此意用于疑問句，常與you 連用Will you give me a piece of paper?Would 表過去反復(fù)的動(dòng)作/某種傾向 (相對(duì)于 used to 無“現(xiàn)已無此習(xí)慣”之義。 )此意表對(duì)目前事物的預(yù)料。Thatwill be the postman ringing.(would 表示過去 /現(xiàn)在； will 表示現(xiàn)在 /將來 )敘 述 真 理 ： The tree will leave without water for 3 months.特別提示： would 與 used

21、to 辨析would 可用來表示過去反復(fù)出現(xiàn)的動(dòng)作，但不能表示過去存在的狀態(tài)，所以我們不能說： “ she would be a quiet girl. ”另外， would 強(qiáng)調(diào)過去某種特定情況下的活動(dòng)，是完全過去的事情，同現(xiàn)在沒有聯(lián)系。而used to 則著眼于過去和現(xiàn)在的對(duì)比，隱含現(xiàn)在已不存在，動(dòng)作或狀態(tài)都可表示。Would 可以表示不規(guī)則的習(xí)慣，used to 則不可。如：He used to be a naughty boy and cause trouble.I used to get up at six in the morning.Sometimes she would tak

22、e a walk in the neighboring woods.In those days, whenever I had difficulties, I would go to Mr. Chen for help.六 need 和 dare情態(tài)動(dòng)詞用法例句用于表示“需要，必要”之意。做情態(tài)動(dòng)詞時(shí)，僅用于否定句和疑問句，只有現(xiàn)在時(shí)，過去式要用 needn't have，疑問式用 need+人稱 ?,否定式用 need not(即needn't），做實(shí)義動(dòng)詞時(shí)，其變化與一般的實(shí)義動(dòng)詞相同，后接帶 to 的不定式（ need doingneed= need to be done

23、 ）,過去式用 needed 、did you need? 和 didn't need, 肯定式用needs/needed/need, 疑問式用 do、does 、 did 提問，否定式要在前面加1 Need we leave soon? Yes, you must.(No, you needn't)2 You needn't have hurried.(=It was not necessary for you to hurry ， but you did). 你當(dāng)時(shí)不必這么匆忙。1. A job like nursing needs patience and und

24、erstanding.(need+ 名詞， need understanding=need to be understood,需要被理解 )2 He needs to see a doctor.(need to do)3 Do you still need volunteers to help clean up after the party?(need somebody to do something)4 They didn't need to start so early.(do not need to do)don't 、doesn't 、didn'tda

25、re用于表示“敢于”之意。做情態(tài)動(dòng)詞，沒有人稱和數(shù)的變化，主要用于否定句、疑問句和條件狀語從句中用作實(shí)義動(dòng)詞時(shí)，其變化與一般的實(shí)義動(dòng)詞相同。在肯定句中，dare 后接帶to的不定式；否定句中，dare 后既可接帶to 的不定式，也可接不帶to 的不定式。1 Dare you tell her the truth? Yes, I dare. /No, I daren t.3 How dare you accuse me of lying!4 He darentadmit this.1 Only a few journalists dared to cover the story.2 He doe

26、sntdare (to) go there alone.3 Don tyou dare (to) touch it?七 ought 的用法：情態(tài)動(dòng)用法例句詞表示“應(yīng)該”之意1 You ought to take care of him.Should2 Ought I go now?補(bǔ)充說明（ 1） should 用于疑問句中表示說話人對(duì)某事不能理解， 惋惜，感到 Yes, you ought to. /No,yououghttooughtntto.do表示推測(cè)。 注意與 must 表示推1 He must be home by now. (斷定他測(cè)是的區(qū)別已到家 )2 He ought to

27、be home by now. (不十分肯定 )3 This is where the oil must be. (比較直率 )4 This is where the oil ought to be. ( 比較含蓄 )意外， 贊 嘆，憤怒、 驚異等感情，意為“竟會(huì)” ，有時(shí)也用于陳述句中 （ 2） 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。說明： should 與 ought to 表示“應(yīng)該”時(shí)的區(qū)別should 表示自己的主觀看法，而 ought to 的語氣中，含有“按道理應(yīng)該 ”之意。若要反映客觀情況或

28、涉及法律義務(wù)和規(guī)定，一般用 ought to。如：You should help them with their work.You are his father. You ought to get him to receive good education.八“情態(tài)動(dòng)詞 +have done”用法情態(tài)動(dòng)詞 +have done用法must have done表示主觀上對(duì)過去已經(jīng)發(fā)生的行為進(jìn)行推測(cè)，意為“想必， 準(zhǔn)是，一定做了某事”may/might have done表示對(duì)過去已發(fā)生行為的推測(cè)，意為“也許/或許已經(jīng)（沒有） “。一般用于肯定句或否定句中， 不用于疑問句。 用 might則表示語

29、氣更加不肯定。例句1 She must have gone through a lot.2 He must have visited the White House during his stay in the United States.1 You may have learnt the news.2 He may not have heard his name called.3 Sorry I m late. I might have turned off the alarm clock and gone back to sleep again.can have done cannot h

30、ave donecould have done表示對(duì)過去發(fā)生的行為的懷疑和不肯定，通常用在否定句和疑問句中。（ can 換成could 時(shí)語氣委婉）可用于肯定句中，表示“可能已經(jīng) ”之意，此外，還可以表示過去能做而沒做的事，有一種對(duì)過去為付諸實(shí)施的事情的惋惜。1 Where can she have gone?2 Could he have done such a foolish thing?3 The boy canthave finished reading the book so soon because it is difficult even to an adult.1 He could have killed himself driving at a dangerous speed.2 You could have been more considerate.3 You could have done better, but yo