英語情態(tài)動(dòng)詞總結(jié).doc

情態(tài)動(dòng)詞1、情態(tài)動(dòng)詞的基本用法 (1)can、could 和be able tocan和couldcan和could表示: 1)能力、技能（理論上）2)請(qǐng)求、允許（肯定回答只能用can,不能用could）3)可能性（理論上） The road can/may be blocked. 區(qū)別？could比較委婉客氣，回答時(shí)則用can。如： Could you help me carry the bag? Yes, I can.can和be able to都表示能力，區(qū)別為：can只有現(xiàn)在和過去時(shí)，而be able to則有更多的形式，如will be able tocan表示理論上的，一般的能力；成功地完成某一具體動(dòng)作時(shí)，用be(was/were) able to。這時(shí)was/were able to 相當(dāng)于managed to，表示經(jīng)過一番努力，終于能夠完成某事。如： Can you use chopsticks?The wounded man still was able to get to the village and was saved in the end.(2) may/mightmay/might表示：1)可能性 （may比might可能性大）2)允許,請(qǐng)求（might表示比較委婉的語氣，回答用may） May / Might I use your bike?Yes, you can / may.No, you mustnt3)祝愿 may+主+謂（動(dòng)詞原形）May you succeed.=Wish you success.（3）mustmust表示:1)必須，應(yīng)該 You must do everything as I do. -Must? -Yes, you must. / No, you neednt. No, you dont have to.2)肯定的推測(cè) The light is still on, so he must be at home.3)mustnt 表示禁止做某事 You mustnt smoke in the office.（4）have tohave to 表示“必須、不得不”，是由于某種外界（客觀）原因而“必須”，“不得不”做某事。dont have to表示不必。have to可用于多種時(shí)態(tài)中。如： You will have to clean your own boots when you join the army. I have to be at my office every evening.（5）should / ought toshould和ought to表示:1)應(yīng)當(dāng)、應(yīng)該 前者比后者語氣輕 2)否定形式表示禁止 Children shouldnt smoke.3)勸告 You ought to respect your parents.Should:1)第一人稱委婉語氣：I should think it would be better to try it again. 我倒是認(rèn)為 2)if條件句中，萬一：Ask her to ring me up if you should see her. 3)竟然4)推測(cè)（按理來說）must和have to的區(qū)別？must和should/ought to的區(qū)別？（6）will / wouldwill/would表示：1)意志、意愿、決心 否定式wont, if I will2)請(qǐng)求、詢問 (常用在第二人稱時(shí)表示說話人向?qū)Ψ? Will/Would you please tell her the news when you see her?3)will 表示習(xí)慣性的動(dòng)作 Fish will die out of water.would 表示過去反復(fù)發(fā)生的動(dòng)作 When I passed my school I would see my teachers who taught me 5 years ago.（7）needneed 作“必要”講，既可作情態(tài)動(dòng)詞，也可作實(shí)義動(dòng)詞。作實(shí)義動(dòng)詞時(shí)后面的動(dòng)詞不定式要帶to，其變化與一般動(dòng)詞相同。如： I need to think it over.Need you go now? Yes, I must. /No, I neednt.（8）daredare表示“敢”的意思。作為情態(tài)動(dòng)詞時(shí)，主要用在疑問句和否定句中。有過去式dared。dare若作實(shí)義動(dòng)詞，后面可帶to的不定式，此時(shí)to也可以省略。dare與need的用法相似。如： How dare you say that? She doesnt dare(to)ask her father.（9）used toused to表示過去常常發(fā)生的動(dòng)作或存在的習(xí)慣，但現(xiàn)在已不復(fù)存在了。如： He used to smoke.（10）shallshall表示：1）用于二、三人稱，表示說話人的意愿，有“命令”、“警告”、“威脅”、“強(qiáng)制”、“允許”等意思。如：1You shall pay for this. 你要為此付出代價(jià)。（threat）2You shall have a car for your birthday. 你過生日會(huì)得到一輛汽車。（promise）3 When he comes in nobodyshall say a word.他進(jìn)來的時(shí)候，誰也不許說話。（command）4Sorry, sir. But it is the management rules of our hotel that payment shall be made in cash.對(duì)不起，先生，我們酒店規(guī)定（顧客）得付現(xiàn)金。(regulation)5Its getting dark. Shall I turn on the light? 天黑了，我把燈打開好嗎？(request)2)用于第一、第三人稱,征求對(duì)方的意見或請(qǐng)求。如： Where shall he wait for us? Shall we go out for a walk?3)用于法律、法令或正式文件。如：The fine should be paid in cash.2、情態(tài)動(dòng)詞表示推測(cè)或判斷的用法下表即是表示推測(cè)的情態(tài)動(dòng)詞使用的場合：情態(tài)動(dòng)詞 對(duì)現(xiàn)在和未來的推測(cè) 對(duì)過去的推測(cè) Must must + 動(dòng)詞原形 must have done may / might may / might + 動(dòng)詞原形 May / might have done can /could can / could do can / could have done例如：(1) can:表可能性多用于否定與疑問結(jié)構(gòu)中，但也可用在肯定句中。Can the news be true? 這消息可能是真的嗎？It cant be true. 它不可能是真的。What can he possibly mean? 他可能是什么意思？can 用在肯定句中表示理論上的可能性（一時(shí)的可能）。A horse in the center ofLondoncan cost a lot of money.Attending the ball can be very exciting.The road can be blocked. 這條路可能會(huì)不通的。Could表過去的可能和許可 。（多用于間接引語中）At that time we thought the story could not be true.那時(shí)我們認(rèn)為所說的事不可能是真的。Father said I could swim in the river.爸爸說我可以在河里游泳。Could/can have done 結(jié)構(gòu)表示對(duì)過去發(fā)生的事情的“懷疑”或“不肯定”。 Can they have won the basketball match？他們贏了那場籃球賽嗎？What you referred to just now can have made her very sad.你剛剛所談到的可能令他很傷心。You could have completed the task a little earlier.你本來能早點(diǎn)完成任務(wù)的。（但事實(shí)上并沒有提前完成任務(wù)）I could have passed my examination easily but I made too many stupid mistakes.我本可以輕易通過考試，但我犯了太多不該犯的錯(cuò)誤。(2)may 在肯定句中表示現(xiàn)實(shí)的可能性。The road may be blocked. 這條路可能不通了。may /might 推測(cè)性用法 可能He may be right.He may not come today. (可能不)He may /might come tomorrow.注意 : (1)只用于肯定和否定句中,不用于疑問句中。（2）might 比may可能性更小 (3) may no 可能不 can not不可能may (might) have done 表示對(duì)過去發(fā)生行為的推測(cè)，含有“想必”、“也許是”的意思。It may have been true. 這事也許是真的。He might not have settled the question. 他可能尚未解決那個(gè)問題。It must have rained last night.They should be there right now.3、情態(tài)動(dòng)詞在虛擬語氣中的用法（1）should have done表示“本來應(yīng)該做某事而實(shí)際上未做” ought to have doneshouldnt have done表示“本不應(yīng)該做某事而實(shí)際上做了” oughtnt to have doneYou should have told me about it earlier.You shouldnt have said such words to your parents.（2）neednt have done表示“本無必要做某事而實(shí)際上做了”You neednt have walked so quickly since time was enough.（3）could have done表示“本來有可能,可以而事實(shí)上未做到”I could have come on time, but my car broke on the way.四：情態(tài)動(dòng)詞+行為動(dòng)詞進(jìn)行式情態(tài)動(dòng)詞+行為動(dòng)詞進(jìn)行式（即情態(tài)動(dòng)詞+ be + v.-ing形式），表示推測(cè)或評(píng)論某動(dòng)作現(xiàn)在是否正在進(jìn)行。例如：1）He must be playing basketball in the room.2）She may be staying at home.五.情態(tài)動(dòng)詞+行為動(dòng)詞完成進(jìn)行式情態(tài)動(dòng)詞+行為動(dòng)詞完成進(jìn)行式（即情態(tài)動(dòng)詞+ have been + v.-ing 形式），表示推測(cè)或評(píng)論過去某動(dòng)作是否正在進(jìn)行或一直在進(jìn)行。例如：1）They should have been meeting to discuss the problem.2）He may / might have been buying stamps in the post office when you saw him.六.used to +v., be used to +v.-ing和be used to +v.（1）used to +v.“過去常?！?，“過去一直”；be used to +v.-ing / n.（名詞）“習(xí)慣于”；be used to +v.“被用來（做某事）”。（2）used to只表示過去，而be used to +v.-ing / n可表示現(xiàn)在、過去或?qū)怼＠纾?）He used to smoke. Now he doesnt.2）Hes quite used to hard work / working hard.3）The knife is used to cut bread.七用作情態(tài)動(dòng)詞的其他短語would rather, would sooner, would (just) as soon, had rather, had better, had sooner, can not but, may (just) as well等可用作情態(tài)動(dòng)詞。例如：1）The soldier would sooner die than surrender.2）The brave soldier would as soon die as yield to such an enemy.3）Id rather walk than take a bus.4）If you dont like to swim, you may just as well stay at home.注：這些短語后一般直接跟動(dòng)詞原形.would (had) rather, would (had) sooner, would (just) as soon后可跟that 引導(dǎo)的從句，that 常省去，從句要用虛擬語氣。對(duì)現(xiàn)在和