語(yǔ)法專題5 情態(tài)動(dòng)詞和虛擬語(yǔ)氣(Ivan Fang)

情態(tài)動(dòng)詞modal verbs情態(tài)動(dòng)詞情態(tài)動(dòng)詞表示推測(cè)表示推測(cè)不表示推測(cè)不表示推測(cè)can couldmay mightshall shouldmust will wouldought tohave to dare (darent)need (neednt) used to可兼做行為動(dòng)詞的情態(tài)動(dòng)詞：可兼做行為動(dòng)詞的情態(tài)動(dòng)詞：need 、 dare 情態(tài)動(dòng)詞 (+動(dòng)詞原形)行為動(dòng)詞 .needdare 1.1.無(wú)人稱和數(shù)的變化無(wú)人稱和數(shù)的變化; 2.2.尤其用于：尤其用于：* *否定句及疑問(wèn)句中否定句及疑問(wèn)句中; ;* *在在if/whetherif/whether之后之后; ;* *或與或與hardlyhardly, , nevernever, , no oneno one, , nobodynobody連用連用; ; 3. 3.常以常以needntneednt 和和darentdarent 的形式出現(xiàn)的形式出現(xiàn); ;4.dare4.dare有其過(guò)去時(shí)有其過(guò)去時(shí)dareddared. . 多用于肯定句多用于肯定句; (sb.) need to do dare to do(sth.) need to be done (sth.) need doing 注意對(duì)注意對(duì)need問(wèn)句的回答問(wèn)句的回答: -Need I finish the work today? -Yes, _. No, _. No, _.you mustyou needntyou dont have toneednt 對(duì)其它情態(tài)動(dòng)詞的回答對(duì)其它情態(tài)動(dòng)詞的回答: -Shall I tell John about it? -No, you _. -Must we do it now? -No, you _. neednt (dont have to) neednt(dont have to)表示推測(cè)表示推測(cè)情態(tài)動(dòng)詞的重要用法情態(tài)動(dòng)詞的重要用法. .肯定的推測(cè)肯定的推測(cè)可能的推測(cè)可能的推測(cè)否定的推測(cè)否定的推測(cè)疑問(wèn)的推測(cè)疑問(wèn)的推測(cè)must 對(duì)將來(lái)對(duì)將來(lái) 對(duì)現(xiàn)在對(duì)現(xiàn)在 對(duì)過(guò)去對(duì)過(guò)去情態(tài)動(dòng)詞情態(tài)動(dòng)詞may, might cant, couldntcan, could + V. + V. + have done常見(jiàn)常見(jiàn)must be + be doing + V. + V. + have done + be doing 可以用可以用not表示表示“可能不可能不” +V. + V. + have done + be doing+ V. + V. + have done + be doing不同的不同的“肯定肯定”程度可按下列層次排列：程度可按下列層次排列： He is at home. (事實(shí)事實(shí)) He must be at home.（非?？隙ǖ耐茢啵ǚ浅？隙ǖ耐茢啵?He could be at home.（很可能）（很可能） He ought to be at home.（很可能）（很可能） He may be at home.（僅僅可能而已）（僅僅可能而已） He might be at home.（或許（或許, 非常不確定）非常不確定） He might not be at home.（也許不在家）（也許不在家）He may not be at home. （比（比might可能可能） He couldnt be at home.（很可能不在家）（很可能不在家） He cant be at home.（一定不在家）（一定不在家）He isnt at home.（事實(shí)）（事實(shí)） 在不表示推測(cè)的情態(tài)動(dòng)詞中在不表示推測(cè)的情態(tài)動(dòng)詞中, 我們要注意以下考點(diǎn)我們要注意以下考點(diǎn):1. 表示能力、許可的情態(tài)動(dòng)詞的用法。表示能力、許可的情態(tài)動(dòng)詞的用法。2. 表示否定的情態(tài)動(dòng)詞的用法。表示否定的情態(tài)動(dòng)詞的用法。3. shall 和和 will 的多種意義的區(qū)別。的多種意義的區(qū)別。4. 情態(tài)動(dòng)詞短語(yǔ)的使用。情態(tài)動(dòng)詞短語(yǔ)的使用。5. 虛擬語(yǔ)氣中情態(tài)動(dòng)詞的使用。虛擬語(yǔ)氣中情態(tài)動(dòng)詞的使用。 表示能力表示能力: can, could, be able to *be able to 能用于能用于各種時(shí)態(tài)各種時(shí)態(tài)。 can / could 只能表示只能表示現(xiàn)在現(xiàn)在或或過(guò)去過(guò)去的能力。的能力。 *was / were able to : “設(shè)法做成某事設(shè)法做成某事” 相當(dāng)于相當(dāng)于 managed to do sth. succeeded in doing sth.。1. 表示能力、許可的情態(tài)動(dòng)詞的用法。表示能力、許可的情態(tài)動(dòng)詞的用法。表示許可表示許可: may / might, can / could * might, could 比較比較委婉委婉, 一般多用于一般多用于疑問(wèn)句疑問(wèn)句.* can, may 表達(dá)的語(yǔ)言比較隨便表達(dá)的語(yǔ)言比較隨便.* 在以在以could, might 表示表示征詢對(duì)方意見(jiàn)征詢對(duì)方意見(jiàn) 或或表示請(qǐng)求表示請(qǐng)求時(shí)，回答應(yīng)相應(yīng)使用時(shí)，回答應(yīng)相應(yīng)使用can, may.2. 表示否定的情態(tài)動(dòng)詞的用法表示否定的情態(tài)動(dòng)詞的用法: 部分情態(tài)動(dòng)詞的否定式是情態(tài)動(dòng)詞中的考點(diǎn)部分情態(tài)動(dòng)詞的否定式是情態(tài)動(dòng)詞中的考點(diǎn)之一。之一。 mustnt 不準(zhǔn)不準(zhǔn), 禁止禁止 neednt 沒(méi)必要沒(méi)必要 ( = dont have to )cant 不能不能; 不可能不可能may not 不可以不可以; 可能不可能不shouldnt 不應(yīng)該不應(yīng)該 ( = ought not to )情態(tài)動(dòng)詞：情態(tài)動(dòng)詞：shall, will 的多種意義的多種意義: shall / will+ 動(dòng)詞原形動(dòng)詞原形: * shall 可表示必須、命令、可表示必須、命令、 警告或征詢意見(jiàn)警告或征詢意見(jiàn). * will 可表示意愿、常出現(xiàn)的動(dòng)作、在疑問(wèn)句可表示意愿、常出現(xiàn)的動(dòng)作、在疑問(wèn)句 中表示請(qǐng)求和建議中表示請(qǐng)求和建議.* 均可表示將來(lái)。均可表示將來(lái)。 過(guò)去時(shí)為過(guò)去時(shí)為 should, would.3.Good-bye!1.英語(yǔ)動(dòng)詞有三種語(yǔ)氣， 陳述語(yǔ)氣，祈使語(yǔ)氣和虛擬語(yǔ)氣。2. 定義：用來(lái)表示說(shuō)的話不是事實(shí)，或者是不可能發(fā)生的情況，而是一種愿望，建議，假設(shè)的語(yǔ)氣叫虛擬語(yǔ)氣。一、虛擬語(yǔ)氣在非真實(shí)條件狀語(yǔ)從句中的用法一、虛擬語(yǔ)氣在非真實(shí)條件狀語(yǔ)從句中的用法虛擬條件句主句例句與現(xiàn)在事實(shí)相反動(dòng)詞過(guò)去式動(dòng)詞過(guò)去式（be都用都用were）should/would/could/might+動(dòng)動(dòng)詞原形詞原形If I had time, I would attend the meeting.If I were you, I should seize the chance to go abroad.與過(guò)去事實(shí)相反had+過(guò)去分詞過(guò)去分詞should/would/could/might+ have+過(guò)去分詞過(guò)去分詞If you had taken my advice, you would not have failed in the exams.與將來(lái)事實(shí)相反動(dòng)詞過(guò)去式動(dòng)詞過(guò)去式should+動(dòng)詞原形動(dòng)詞原形 were to+動(dòng)詞原形動(dòng)詞原形should/would/could/might+動(dòng)動(dòng)詞原形詞原形If you came tomorrow, we would have the meeting.If it were to rain tomorrow, the sports meeting would be put off.If he should not come tomorrow, we should put off the meeting till next Monday. 1. 省略省略if 的虛擬倒裝句（的虛擬倒裝句（were,had,should)e.g. If it should rain tomorrow, we would not go climbing. =Should it rain tomorrow, we would not go climbing. 2. 錯(cuò)綜時(shí)間條件句錯(cuò)綜時(shí)間條件句(時(shí)間不一致）時(shí)間不一致）e.g. If you had followed my advice just now, you would be better now.3.含蓄條件句（含蓄條件句（with; without; but for, otherwise) e.g. What would you do with a million dollars?(=if you had a million dollars)注意事項(xiàng)：注意事項(xiàng)：二、名詞性從句：二、名詞性從句：1.賓語(yǔ)從句。常見(jiàn)動(dòng)詞：一個(gè)堅(jiān)持：insist兩個(gè)命令命令：order, command 三個(gè)建議建議：advise, suggest, propose四個(gè)要求：要求：demand , require, request, desire 賓語(yǔ)從句中的動(dòng)詞 使用should + V，或者將should省略。 2.主語(yǔ)從句，表語(yǔ)從句和同位語(yǔ)從句。 常見(jiàn)名詞： order, advice, suggestion, order, advice, suggestion, proposal, demand, request, desire proposal, demand, request, desire It is suggested thatIt is suggested that he he should thereshould there at once at onceMy suggestion is thatMy suggestion is that he he should thereshould there at once at onceI made a suggestion thatI made a suggestion that he he should thereshould there at once. at once.從句中的動(dòng)詞 使用should + V，或者將should省略This is the suggestion This is the suggestion that/whichthat/which he he mademade at the meeting. at the meeting.二、虛擬語(yǔ)氣特殊句型：1. wish + 賓語(yǔ)從句現(xiàn)在：過(guò)去：未來(lái)：過(guò)去時(shí) (did/were)過(guò)去完成時(shí) (had done)would/could/might+V. should2. would rather that -現(xiàn)在：過(guò)去：未來(lái)：過(guò)去時(shí)過(guò)去時(shí)過(guò)去完成時(shí)3. as if /though + 從句現(xiàn)在：過(guò)去：過(guò)去時(shí)過(guò)去完成時(shí)4.Its (about/high) time +that -should +V.過(guò)去時(shí)5. If only 現(xiàn)在：過(guò)去：未來(lái)：過(guò)去時(shí)過(guò)去完成時(shí)could +V.6. Its necessary /strange/ natural/ important + that - (should)+動(dòng)詞原形動(dòng)詞原形7. 某些簡(jiǎn)單句的固定句型：某些簡(jiǎn)單句的固定句型： Heaven help him! God bless you! May you succeed! Long live the Peoples Republic of China!