助動詞與情態(tài)動詞ppt課件

1、GrammarGrammar1. 情態(tài)動詞沒有人稱和數(shù)的變化情態(tài)動詞沒有人稱和數(shù)的變化,即情即情態(tài)動詞第三人稱單數(shù)不加態(tài)動詞第三人稱單數(shù)不加- s (have to, have got to, be able to 除外除外)。2. 情態(tài)動詞本身具有一定詞義情態(tài)動詞本身具有一定詞義, 但意但意思不夠完整思不夠完整, 不能單獨做謂語不能單獨做謂語, 后后接動詞原形一起構(gòu)成謂語部分接動詞原形一起構(gòu)成謂語部分 (ought to, have to/have got to, be able to除外除外)。3. 情態(tài)動詞無非謂語形式情態(tài)動詞無非謂語形式,即無不定即無不定式、分詞等形式。式、分詞等形式。

2、Sum up1. can和和be able to1) can (could) 表示能力、能夠表示能力、能夠, 只用于現(xiàn)在式和過去式只用于現(xiàn)在式和過去式2) be able to可以用于各種時態(tài)?？梢杂糜诟鞣N時態(tài)。只用只用be able to的情況：的情況： a. 位于助動詞后。位于助動詞后。Has/have been able tob. 情態(tài)動詞后。情態(tài)動詞后。 We must/may be able to Show How Science is Beneficial to c. 用于句首表示條件。用于句首表示條件。 Being able to get the tickets for that

3、 Hockey game, I am very excited now. 能買到那個冰球比賽的票，我現(xiàn)在非常激動。能買到那個冰球比賽的票，我現(xiàn)在非常激動。 d. 表示成功地做了某事時表示成功地做了某事時,只能用只能用was/ were able to,不能用不能用could。留意留意:could:could還可不表示時態(tài)還可不表示時態(tài), ,只表示只表示1) 1) 提出委婉的請求提出委婉的請求, ,回答中不可用回答中不可用couldcould。 - Could I have the - Could I have the television on?television on? - Yes, yo

4、u can. / No, you - Yes, you can. / No, you cant.cant.2) 2) 在否定、疑問句中表示推測或懷疑。在否定、疑問句中表示推測或懷疑。 He couldnt be a bad man. He couldnt be a bad man.2. may和和might1) 表示允許或請求表示允許或請求;表示沒有把握的表示沒有把握的推測推測;may 放在句首放在句首,表示祝愿。表示祝愿。e.g. May God bless you! He might be at home.注注: might 表示推測時表示推測時,不表示時態(tài)。不表示時態(tài)。只是可能性比只是可

5、能性比may 小。小。2) 成語成語:may/might as well,后面接后面接不帶不帶to 的不定式，意為的不定式，意為無妨無妨。 e.g. If that is the case, we may as well try.3. have to和和must1) 兩詞都是兩詞都是“必需的意思必需的意思, have to 表表示客觀的需要示客觀的需要, must 表示說話人主表示說話人主觀上的看法觀上的看法, 即主觀上的必要。即主觀上的必要。e.g. My brother was very ill, so I had to call the doctor in the middle of t

6、he night. He said that they must work hard. 2) have to有人稱、數(shù)、時態(tài)的變化有人稱、數(shù)、時態(tài)的變化,而而must只有一種形式。但只有一種形式。但must可用于可用于 間接引語中表示過去的必要或義務(wù)。間接引語中表示過去的必要或義務(wù)。 e.g. He had to look after his sister yesterday.3) 在否定結(jié)構(gòu)中：在否定結(jié)構(gòu)中：dont have to 表示表示“不不用用”; mustnt表示制止表示制止”。e.g. You dont have to tell him about it. 你不必把這事告訴他。你

7、不必把這事告訴他。 You mustnt tell him about it. 你不能把這事告訴他。你不能把這事告訴他。 4. must表示推測表示推測1) must用在肯定句中表示較有把用在肯定句中表示較有把握的推測握的推測,意為意為“一定一定”。2) must表對現(xiàn)在的狀態(tài)或現(xiàn)在正表對現(xiàn)在的狀態(tài)或現(xiàn)在正發(fā)生的事情的推測時發(fā)生的事情的推測時, 后面通常后面通常接系動詞接系動詞be的原形或行為動詞的原形或行為動詞的進(jìn)行時。的進(jìn)行時。 e.g. You have worked hard all day. You must be tired.（對現(xiàn)在情況的（對現(xiàn)在情況的推測判斷推測判斷) He m

8、ust be working in his office. 他一定在辦公室工作呢。他一定在辦公室工作呢。比較比較: He must be staying there. 他現(xiàn)在肯定呆在那兒。他現(xiàn)在肯定呆在那兒。 He must stay there. 他必須呆在那兒。他必須呆在那兒。表推測表推測不表推測不表推測3) must 表示對已發(fā)生的事情的推表示對已發(fā)生的事情的推測時測時, 要接完成時。要接完成時。e.g. I didnt hear the phone. I must have been asleep.4) must表示對過去某時正發(fā)生的表示對過去某時正發(fā)生的事情的推測事情的推測, 后面要

9、接不定式的后面要接不定式的完成進(jìn)行時。完成進(jìn)行時。e.g. -Why didnt you answer my phone call? -Well, I must have been sleeping, so I didnt hear it. 5) 否定推測用否定推測用cant.e.g. If Tom didnt leave here until five oclock, he cant be home yet.5.表示推測的用法表示推測的用法 can, could, may, might, must 皆可表皆可表 示推測示推測,其用法如下：其用法如下： 1) 情態(tài)動詞情態(tài)動詞+動詞原形動詞原形

10、,表示對現(xiàn)在表示對現(xiàn)在或?qū)淼那闆r的推測或?qū)淼那闆r的推測,此時動詞通此時動詞通常為系動詞。常為系動詞。 e.g. I dont know where she is. She may be in Wuhan.2) 情態(tài)動詞情態(tài)動詞+動詞進(jìn)行時動詞進(jìn)行時, 表示對現(xiàn)在或表示對現(xiàn)在或?qū)碚谶M(jìn)行的情況進(jìn)行推測。將來正在進(jìn)行的情況進(jìn)行推測。 e.g. At this moment, our teacher must be correcting our exam papers.3) 情態(tài)動詞情態(tài)動詞+動詞完成時動詞完成時, 表示對過去情表示對過去情況的推測。況的推測。e.g. The road is

11、wet. It must have rained last night. 4) 情態(tài)動詞情態(tài)動詞+動詞的完成進(jìn)行時動詞的完成進(jìn)行時, 表表示對過去正在發(fā)生事情的推測。示對過去正在發(fā)生事情的推測。 e.g. Your mother must have been looking for you. 5) 推測的否定形式推測的否定形式,疑問形式用疑問形式用cant, couldnt表示。表示。 e.g. Mike cant have found his car, for he came to work by bus this morning. 注注: could, might表示推測時不表示時態(tài)表示推

12、測時不表示時態(tài),其推測的肯定程度不如其推測的肯定程度不如can, may。6.情態(tài)動詞情態(tài)動詞+have+過去分詞過去分詞1) may (might) have + done sth., can (could) have + done sth. 表示過去表示過去,推測過去時間里可能發(fā)生的事情。推測過去時間里可能發(fā)生的事情。e.g. Philip may (might) have been hurt seriously in the car accident. Philip can (could) have been hurt seriously in the car accident.2) m

13、ust have+done sth., 表示對過去表示對過去時間里可能發(fā)生的事情的推測時間里可能發(fā)生的事情的推測,語語氣較強氣較強,具有具有“一定的意思。一定的意思。e.g. - Linda has gone to work, but her bicycle is still here. - She must have gone by bus.3) ought to have done sth./should have done sth.本應(yīng)該做某事本應(yīng)該做某事,而事實上并而事實上并沒有做沒有做; 否定句表示否定句表示“不該做某事而不該做某事而做了做了”。e.g. You ought to (

14、should) have been more careful in this experiment. He ought not to have thrown the old clothes away.(事實上已扔了。事實上已扔了。)注注: ought to 在語氣上比在語氣上比should 要強。要強。4) neednt have done sth. 本沒必要做某事本沒必要做某事e.g. I dressed very warmly for the trip, but I neednt have done so. The weather was hot.5) would like to have

15、 done sth. 本打算做本打算做某事某事e.g. I would like to have read the article, but I was very busy then.7. should和和ought to should 和和ought to 都為都為“應(yīng)該的意應(yīng)該的意思思,可用于各種人稱。可用于各種人稱。e.g. - Ought he to go? - Yes. I think he ought to. 表示要求表示要求,命令時命令時,語氣由語氣由 should(應(yīng)應(yīng) 該該)、(had better最好最好)、must(必需必需) 漸強。漸強。8. had better表示表

16、示“最好最好” had better 相當(dāng)于一個助動詞相當(dāng)于一個助動詞,它它只有一種形式只有一種形式,它后面要跟動詞原它后面要跟動詞原形。形。 had better (not) do sth.e.g. It is pretty cold. Youd better put on my coat. Shed better not play with the dog. had better have done sth. 表示與事實相反的結(jié)果表示與事實相反的結(jié)果,意為意為“(過去過去)本來最好本來最好”。e.g. You had better have come earlier.9. would ra

17、ther表示表示“寧愿寧愿” would rather (not) do would ratherthan寧愿寧愿而不愿而不愿 would sooner had rather had sooner表示表示寧愿寧愿、寧可寧可的意思。的意思。e.g. If I have a choice, I had sooner not continue my studies at this school.10. will和和would1) would like to do = want to 想要想要 e.g. Would you like to go with me?2) Will you? / Would

18、 you like? 表示肯定含義的請求勸說時表示肯定含義的請求勸說時,疑問句疑問句中一般用中一般用some, 而不是而不是any。e.g. Would you like some cake?3) 否定結(jié)構(gòu)中用否定結(jié)構(gòu)中用will, 一般不用一般不用would, wont you是一種委婉語氣。是一種委婉語氣。e.g. Wont you sit down?11. need和和dare 這兩詞既可做實義動詞用這兩詞既可做實義動詞用,又可做情又可做情態(tài)動詞用。作為情態(tài)動詞態(tài)動詞用。作為情態(tài)動詞,兩者都常用兩者都常用于疑問句于疑問句,否定句和條件句。并注意回否定句和條件句。并注意回答用答用need

19、提問的句子時，肯定回答用提問的句子時，肯定回答用must。 need 作實義動詞時后面的不定式必作實義動詞時后面的不定式必須帶須帶to,而而dare作實義動詞用時作實義動詞用時, 后面的后面的to時?？梢员皇÷?。時?？梢员皇÷浴?) 實義動詞實義動詞: need+ n. / to do sth.2) 情態(tài)動詞情態(tài)動詞: need,只用原形只用原形need后加后加do,否定形式為否定形式為need not.e.g. - Need you go yet? - Yes, I must. / No, I neednt.3) need, want, require, worth(形容詞形容詞)后面接后面

20、接doing也可以表示被動。也可以表示被動。 need doing = need to be done高考鏈接高考鏈接 I cant find my purse anywhere. You _ have lost it while shopping. (重慶重慶2019) A. may B. can C. should D. wouldA 2. Although this _ sound like a simple task, great care is needed. (四川四川2019) A. must B. may C. shall D. should3. You _ be hungry

21、 already you had lunch only two hours ago! (浙江浙江2019) A. wouldnt B. cant C. mustnt D. needntB B 4. Im sorry. I _ at you the other day. Forget it. I was a bit out of control myself. (江蘇江蘇2019) A. shouldnt shout B. shouldnt have shouted C. mustnt shout D. mustnt have shoutedB 5. According to the air t

22、raffic rules, you _ switch off your mobile phone before boarding. (上海上海2019) A. may B. can C. would D. should6. When I was young, I was told that I _ play with matches. (2019上海春上海春) A. wouldnt B. neednt C. mustnt D. darentD C 7. It is usually warm in my hometown in March, but it _ be rather cold som

23、etimes. (福建福建2019) A. mustB. can C. should D. would 8. You dont have to know the name of the author to find a book. You _ find the book by the title. (湖南湖南2019) A. must B. need C. can D. wouldB C 9. What sort of house do you want to have? Something big? Well, it _ be big thats not important. (陜西陜西20

24、19) A. mustnt B. neednt C. cant D. wont10. She _ have left school, for her bike is still here. (天津天津2019) A. cant B. wouldnt C. shouldnt D. needntB A Exercises1. A left-luggage office is a place where bags _be left for a short time, especially at a railway station. A. should B. can C. must D. willB2

25、. How _ you say that you really understand the whole story if you have covered only part of the article? A. can B. must C. need D. mayA3. The room is so dirty. _we clean it? Of course. A. Will B. Shall C. Would D. Do4. My English-Chinese dictionary has disappeared. Who _ have taken it? A. should B.

26、must C. could D. wouldBC5. Is John coming by train? He should, but he _ not. He likes driving his car. A. must B. can C. need D. mayD6. I heard they went skiing in the mountains last winter. It _ true because there was little snow there. A. may not be B. wont be C. couldnt be D. mustnt beC7. It has

27、been announced that candidates _ remain in their seats until all the paper have been collected. A. can B. will C. may D. shall8. I hear youve got a set of valuable Australian coins. _ I have a look? Yes, certainly. A. Do B. May C. Shall D. ShouldDB9. Oh, Im not feeling well in the stomach, I _ so mu

28、ch fried chicken just now. A. shouldnt eat B. mustnt have eaten C. shouldnt have eaten D. mustnt eatC10. I was really anxious about you. You _ home without a word. A. mustnt leave B. shouldnt have left C. couldnt have left D. neednt leaveB11. You cant imagine that a well-behaved gentlemen _ be so ru

29、de to a lady. A. might B. need C. should D. would12. Write to me when you get home. _. A. I must B. I should C. I will D. I canCC13. Mr. Bush is on time for everything. How _it be that he was late for the opening ceremony? A. can B. should C. may D. mustA14. Are you coming to Jeffs party? Im not sur

30、e. I _ go to the concert instead. A. must B. would C. should D. mightD15. My sister met him at the Grand Theatre yesterday afternoon, so he _ your lecture. A. couldnt have attended B. neednt have attended C. mustnt have attended D. shouldnt have attendedA16. Sorry, Im late. I _ have turned off the a

31、larm clock and gone back to sleep again. A. might B. should C. can D. willA17. There was a lot of fun at yesterdays party. You _ come, but why didnt you? A. must have B. should C. need have D. ought to haveD18. When can I come for the photos? I need them tomorrow afternoon. They _ be ready by 12:00.

32、 A. can B. should C. might D. needB19. I stayed at a hotel while in New York. Oh, did you? You _with Barbara. A. could have stayed B. could stay C. would stay D. must have stayedA20. The fire spread through the hotel very quickly but everyone _ get out. A. had to B. would C. was able to D. couldC21. Jack _ yet, otherwise he would have telephoned me. A. mustnt