情態(tài)動詞用法總結.ppt

1、1,米特洋,初中、高中情態(tài)動詞入門,2,定義,情態(tài)動詞是一種本身有一定的詞義,但要與動詞原形及其被動語態(tài)一起使用，給謂語動詞增添情態(tài)色彩，表示說話人對有關行為或事物的態(tài)度和看法，認為其可能、應該或必要等。,情態(tài)動詞后面加動詞原形。,注意,3,分類：,情態(tài)動詞有四類：,只做情態(tài)動詞：must,can(could),may(might),ought to,可做情態(tài)動詞又可做實義動詞：need,dare,可做情態(tài)動詞又可做助動詞：shall(should),will(would),具有情態(tài)動詞特征：have(had,has) to,used to,4,位置:,情態(tài)動詞在句中放在謂語動詞之前, 謂語動

2、詞前若有助動詞,則在助動詞之前,疑問句中, 情態(tài)動詞則在主語之前。,I can 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！,5,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, 時態(tài)性不強, 可用于過去，現(xiàn)在或將來。情態(tài)動詞屬非及物動詞

3、，故沒有被動語態(tài)。,He could be here soon. 他很快就來。 We cant carry the heavy box. 我們搬不動那箱子。 Im sorry I cant help you. 對不起，我?guī)筒簧夏恪?6,The basic uses of Modal Verbs,7,一、 can, could,1) 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）,此時可用be able to代替。（考點一）：Can只有一

4、般現(xiàn)在時和一般過去；而be able to則有更多的時態(tài)。Ill not be able to come this afternoon.,當表示（考點二）“經(jīng)過努力才得以做成功某事”時應用be able to，不能用Can。 如：He was able to go to the party yesterday evening in spite of the heavy rain.,8,一、 can, could,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, might代替，

5、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. ) (考點),9,一、 can, could,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。,Can this be true?

6、 This cant be done by him. 對比：This must be done by him. How can this be true?,10,1. Can,Could 過去式；語氣更委婉,Can 表示習慣能力， 而be able to表示經(jīng)過那里而做成了某事。 2. 在否定結構中，二者可以互換。,1.在否定、疑問句中表示“對過去發(fā)生行為 的可能性猜測。 2. 在肯定句中表示“本來可以做而未做”,The door was lacked. She couldnt have been at home.（推測：） You could have been more careful.（

7、但實事上沒有更細致）,11,二、 may, might,1) 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（考點一）cant或mustnt，表示“不可以，禁止”。,-Might/ May I smoke in this room? - No, you mustnt. - 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，而用Can I.？在口語中更常見。,12,二、 may, might,2）用于

8、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。 1He may /might be very busy now. 2Your mother may /might not know the truth.,13,1. May,Might 過去式；語氣更委婉,1.在否定、肯定句中表示對過去動作的推測 “也許是” 2. Might+have+p.p表示虛擬，表“勸告、責備之意。”,Eg. 1. She may be still waiting for us. 2. May I come in? 3.Ma

9、y you have a happy holiday.,Eg. 1. He might have spoken to her yesterday.（委婉推測） 2. You might have told me earlier.（你或許可以早點告訴我，但實事上沒有，有責備之意）,14,三、 must, have to,1) 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，(考點一)不能用mustnt（禁止，不準），而用neednt, dont have to（不必）.,- Must we hand in our exercise books t

10、oday? - Yes, you must. - No, you dont have to / you neednt.,15,三、 must, have to,2) must是說話人的主觀看法， 而have to則強調客觀需要。Must只有一般現(xiàn)在時， have to 有更多的時態(tài)形式。,He play isnt interesting, I really must go now. 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）,Youre Toms good friend, so you must know what he

11、likes best. Your mother must be waiting for you now.,16,1. Must,表示肯定的猜測,但只用于肯定句， 而mustnt 表示“禁止、不準”,Must表示主觀 Have to表示客觀需求 Have got to 多見于口語,3. must + have +p.p,對過去事情的肯定猜測。,Eg. The road is wet. It must have rained last night.,17,四、 shall, should,1) shall 用于第一人稱，征求對方的意見。,What shall we do this evening?

12、 Shall we go there by bus?,2) shall 用于 (考點一) 第二、三人稱，表示說話人給對方的命令、警告、允諾或威脅。 1. You shall fail if you dont work hard.(警告) 2. He shall have me the book when I finish it.(允諾) 3. He shall be punished.(威脅),18,1、Shall /should,shall/should + have +p.p ought to,表示本應該做而未做。,should 過去式 語氣更委婉,Eg. You should have

13、been five minutes ago.,2、,2、,19,五、 will, would,1) 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.,20,五、 will, would,3) would表示過去反復發(fā)生的動作或某種傾向。would表示過去習慣時比used to正式，且沒有 (考點) “現(xiàn)已無此習慣”的含義。,1. During the

14、vacation, he would visit me every other day. 2. The wound would not heal治愈 . 創(chuàng)傷難以愈合 Would 后只能接表示動作的動詞。used to 則還可以接表示狀態(tài)的動詞。（考點）He used to be a worker.,4) 表示估計和猜想。 It would be about ten oclock when she left home.,21,Will/ would,1、Would 后只能接表示動作的動詞。,2、used to 則還可以接表示狀態(tài)的動詞。 Eg. He used to be a worker.,

15、22,六、 dare, need,1) 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。,How dare you say Im unfair? He darent speak English before such a crowd, dare he? If we dared not go there that day， we couldnt get the beautiful flowers.,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, ought to, should代替。,1You needn

16、t come so early. 2. - Need I finish the work today? - Yes, you must. / No, you neednt.,23,六、 dare, need,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 across this river. 2. He doesnt dare (to) answer. 3. He needs to finish

17、his homework today.,24,1、情態(tài)動詞用于否定、疑問句；條件從句中。 eg. 1. Dare you go here alone? 2. How dare you do such follish things? 3. I wont allow you to swim in the river, even if you dare do it.,Dare / dared,2 、做實意動詞后加不定式。 eg. I have never dared to tell him about it.,25,Need /needed,1、情態(tài)動詞用于否定句，疑問句。,2、實意動詞用法似dar

18、e,用作不定式。,3、need + not + have +p.p 表示“本來不需要做而做了。,26,七、 should, ought to,1) should, ought to表示“應該”，ought to表示義務或責任，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 r

19、ight away. 2. Should I open the window?.,27,七、 should, ought to,3) 表示推測should , ought to (客觀推測), must(主觀推測)。,1.He must be home by now. (斷定他已到家) 2.He ought to/should be home by now.(不太肯定) 3. This is where the oil must be.(直爽) 4. This is where the oil ought to/should be.(含蓄),28,Ought to,1、其否定式為ought n

20、ot to,2、ought to + have + p.p 表示本來應該做而沒有做到。 ought + not+ to have + p.p 表示本不來應該做而實際已做到,You ought to have come here early. You ought not to have cut away the trees around the old building.,29,三點說明,1、情態(tài)動詞 + v 表示對現(xiàn)在或將來動作的猜測。 情態(tài)動詞 + have + p.p表示對過去動作的猜測。,2、情態(tài)動詞的過去式與原形相比，多點禮貌，少點冒昧， 語氣更為委婉。,情態(tài)動詞在一般疑問句中的回答：

21、 Can you sing? May I come in? Must I handin the book now? Need I finish it now?,30,典型錯誤,1. He mustnt be in the classroom. ( ),cant,2. You might leave the bag on the bag. ( ),might have left,3. You must have seen the film last week, havet you? ( ),didnt you,4. Li ming must have been to Japan, didnt h

22、e? ( ),hasnt he,31,米特洋,高中情態(tài)動詞高考要點,32,八、 情態(tài)動詞+不定式完成式（have done）,can / could + have done 在肯定句中表示“本來可以做而實際上能做某事”，是虛擬語氣 在疑問句或否定句中表示對過去行為的懷疑或不肯定, 表示推測。,1. You could have done better, but you didnt try your best. （虛擬語氣） 2. He cant have been to that town.（推測） 3. Can he have got the book?（推測）,33,八、 情態(tài)動詞+不定式

23、完成式（have done）,2) may / might +不定式完成式（have done） 表示對過去行為的推測。不能用于疑問句中，沒有虛擬語氣的用法。Might所表示的可能性比may小。,He may not have finished the work . 他可能沒有做完那項工作 If we had taken the other road, we might have arrived earlier. （條件虛擬） （我們也許會到的更早些）,34,八、 情態(tài)動詞+不定式完成式（have done）,3）must +不定式完成式（have done） 用于肯定句中，表示對過去行為的推

24、測。意為“一定、想必”。其疑問、否定形式用can，cant代替。參看1) can / could + have done表示推測。,You must have seen the film Titanic. He must have been to Shanghai.,must have done sth. 肯定已經(jīng)做了某事（對過去的一種非常肯定的推測） can/could not have done sth. 不可能已經(jīng)做了某事（對過去的一種否定推測） may/might (not) have done sth. 也許已經(jīng)做了某事（對過去的一種大概推測）,推測 小結,35,八、 情態(tài)動詞+不定

25、式完成式（have done）,4）should +不定式完成式（have done） 用于肯定句中，表示對過去行為的推測。,表示“本應該做而實際上沒有做某事”，其否定式表示某種行為本不該發(fā)生卻發(fā)生了?？梢耘cought to +不定式完成式（have done）互換。,He should have finished the work by now。,You ought to / should have helped him. (but you didnt.) She shouldnt have taken away my measuring tape測尺 , for I wanted to u

26、se it.,36,八、 情態(tài)動詞+不定式完成式（have done）,5) neednt +不定式完成式（have done） 表示“本來不必做而實際上做了某事”。,6) will +不定式完成式（have done） 主要用于第二、三人稱，表示對已完成的動作或事態(tài)的推測。,You neednt have watered the flowers, for it is going to rain.,He will have arrived by now.,37,米特洋,情態(tài)動詞表推測小節(jié),38,一、 對現(xiàn)實、現(xiàn)在推測,1) Must 推測（只用于肯定的陳述句）,He must be at ho

27、me now He must know you. He must be waiting for us now.（現(xiàn)在正在進行的推測）,2)can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。,Can this be true? This cant be done by him. 對比：This must be done by him. How can this be true?,注：must+be doing 表示對現(xiàn)在或將來正在發(fā)生的事的推測。According to the weather forecast, it must be snowing tomorrow.,

28、39,一、 對現(xiàn)實、現(xiàn)在推測,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。,He may /might be very busy now. Your mother may /might not know the truth. Tom may not know you are here.,4) will表示猜測 “可能，大概”。 That will be the postman ringing. 按鈴的可能是郵遞員,It would be about ten oclock when she left home. That would be wond

29、erful!,5) would表示估計和猜想。,40,一、 對現(xiàn)實、現(xiàn)在推測,6)表示推測should , ought to (客觀推測), must(主觀推測)。,1.He must be home by now. (斷定他已到家) 2.He ought to/should be home by now.(不太肯定) 3. This is where the oil must be.(直爽) 4. This is where the oil ought to/should be.(含蓄),41,二、 對過去、過去事實推測,1) must + have +p.p對過去事情的肯定猜測,The r

30、oad is wet. It must have rained last night.,2）can./could + have +p.p .在否定、疑問句中表示“對過去發(fā)生行為 的可能性猜測。,The door was lacked. She couldnt have been at home. He cant have been to that town.（推測） Can he have got the book?（推測）,42,二、 對過去、過去事實推測,3) may/might + have +p.p在否定、肯定句中表示對過去動作的推測 “也許是（也許不是）”,He might have spoken to her yesterday.（委婉推測） He might not have known of Nini before.,4）should +have +p.p 用于肯定句中，表示對過去行為的推測。,He should have finished the work by now。,43,二、 對過去、過去事實推測,5) will +不定式完成式（have done)主要用于第二