情態(tài)動詞的基本用法歸納知識交流

1、此文檔僅供收集于網(wǎng)絡(luò)，如有侵權(quán)請聯(lián)系網(wǎng)站刪除情態(tài)動詞的基本用法歸納情態(tài)動詞有can (could), may (might), must, have to, shall (should, will (would), dare (dared),need (needed), ought to 等。 情態(tài)動詞無人稱和數(shù)的變化；不能單獨使用，必須與其后的動詞原形構(gòu)成謂語。一、can, could1) 表示能力（體力、知識、技能）。Can you lift this heavy box? （體力）Mary can speak three languages.（知識）Can you skate?（技能）此

2、時可用 be able to 代替。 Can 只有一般現(xiàn)在時和一般過去式；而be able to 則有更多的時態(tài)。I ll not be able to come this afternoon.當(dāng)表示 “經(jīng)過努力才得以做成功某事”時應(yīng)用 be able to，不能用Can。如：He was able to go to the party yesterday evening in spite of the heavy rain.2) 表示請求和允許。- Can I go now?- Yes, you can. / No, you cant.此時可與may互換。在疑問句中還可用could,migh

3、t代替，不是過去式，只是語氣更委婉，不能用于肯定句和答語中。- Could I come to see you tomorrow?- Yes, you can. ( No, Im afraid not. )3) 表示客觀可能性（客觀原因形成的能力）。Theyve changed the timetable, so we can go by bus instead.This hall can hold 500 people at least.4) 表示推測（驚訝、懷疑、不相信的態(tài)度），用于疑問句、否定句和感嘆句中。只供學(xué)習(xí)與交流此文檔僅供收集于網(wǎng)絡(luò)，如有侵權(quán)請聯(lián)系網(wǎng)站刪除Can this be

4、true?This cantbe done by him. （否定推測）How can this be true?二、may, might1) 表示請求和允許。might 比 may 語氣更委婉，而不是過去式。否定回答時可用cant或 mustnt，表示 “不可以，禁止”。- Might/ May I smoke in this room?- No, you mustn t.- May/Might I take this book out of the room?- Yes, you can. (No, you cant / mustnt. )用 May I. ？征徇對方許可時比較正式和客氣，

5、而用Can I. ？在口語中更常見。2）用于祈使句，表示祝愿。May you succeed!3) 表示推測、可能性（不用于疑問句）。might不是過去式，它所表示的可能性比may小。1 He may /might be very busy now.2 Your mother may /might not know the truth.三、must, have to1) 表示必須、必要。You must come in time.在回答引出的問句時，如果是否定的， 不能用 mustnt（禁止， 不準(zhǔn)），而用 neednt, don thave to（不必） .- Must we hand in

6、 our exercise books today?- Yes, you must.- No, you don t have to / you neednt.2) must 是說話人的主觀看法，而have to則強調(diào)客觀需要。Must只有一般現(xiàn)在時，have只供學(xué)習(xí)與交流此文檔僅供收集于網(wǎng)絡(luò)，如有侵權(quán)請聯(lián)系網(wǎng)站刪除to 有更多的時態(tài)形式。1 he play isnt interesting, I really must go now.2 I had to work when I was your age.3) 表示推測、可能性（只用于肯定的陳述句）1 Youre Toms good frien

7、d, so youmust know what he likes best.（肯定推測 ）2Your mother must be waiting for you now.四、dare, need1) dare 作情態(tài)動詞用時, 常用于疑問句、否定句和條件從句中, 過去式形式為dared。1How dare you say Im unfair?2He daren t speak English before such a crowd, dare he?3 If we dared not go there that day ， we couldn t get the beautiful flow

8、ers.2) need 作情態(tài)動詞用時, 常用于疑問句、 否定句。在肯定句中一般用must, have to, oughtto, should代替。1 You neednt come so early.2. - Need I finish the work today?- Yes, you must. / No, you neednt.3) dare 和need 作實義動詞用時，有人稱、時態(tài)和數(shù)的變化。在肯定句中，dare 后面常接帶to 的不定式。 在疑問句和否定句中，dare 后面可接帶to或不帶to的不定式。 而need后面只能接帶to 的不定式。1. I dare to swim ac

9、ross this river.2. He doesn t dare (to) answer.3. He needs to finish his homework today.五、shall, should1) shall 用于第一人稱，征求對方的意見。What shall we do this evening?2) shall 用于第二、三人稱，表示說話人給對方的命令、警告、允諾或威脅。只供學(xué)習(xí)與交流此文檔僅供收集于網(wǎng)絡(luò)，如有侵權(quán)請聯(lián)系網(wǎng)站刪除1. You shall fail if you dont work警hard告).(2. He shall have the book when I

10、 finish it.( 允諾 )3. He shall be punished.( 威脅 )六、will, would1) 表示請求、建議等， would 更委婉 。Will / Would you pass me the ball, please?2) 表示意志、愿望和決心。1. I will never do that again.2. They asked him if he would go abroad.3) would 表示過去反復(fù)發(fā)生的動作或某種傾向。would 表示過去習(xí)慣時比used to 正式，且沒有 “現(xiàn)已無此習(xí)慣 ”的含義。1. During the vacation

11、, he would visit me every other day.2. The wound would not heal.4) 表示估計和猜想。It would be about ten oclock when she left home.七、should, ought to1) should, ought to 表示 “應(yīng)該 ”， ought to 表示義務(wù)或責(zé)任，比should 語氣重。1. I should help her because she is in trouble.2. You ought to take care of the baby.2) 表示勸告、建議和命令。 should, ought to 可通用，但在疑問句中常用should。1. You should / ought to go to class right away.2. Should I open the window?3) 表示推測should , ought to ( 客觀推測 ), must(主觀推測 )。1.He must be home by