1、山東省郯城第三中學(xué)高中英語 語法大全 第7章 動詞不定式（含鞏固練習(xí)）一.概念: 情態(tài)動詞是表示能力,義務(wù),必須,猜測等說話人的語氣或情態(tài)的動詞.二.相關(guān)知識點精講:1can 1)表能力can表能力時意味著憑體力或腦力或技術(shù)等可以無甚阻力地去做某事。I can climb this pole. 我能爬這根桿子。He is only four , but he can read. 他只有4歲，但已認(rèn)得字了。Fire cant destroy gold. 火燒不毀金子。因為can不能和其他助動詞連用，所以表示將來式時用will be able to You will be able to skat

2、e after you have practiced it two or three times.你練習(xí)兩三次后就會溜冰了。2)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（一時的可能）。A horse in the center of London can cost a lot of money.Attending the ball can be very exc

3、iting.The road can be blocked. 這條路可能會不通的。may 在肯定句中表示現(xiàn)實的可能性。The road may be blocked. 這條路可能不通了。3)表示允許（和may意思相近）常見于口語。Can (May) I come in ? 我能進(jìn)來嗎？Can I smoke here ? 我可以在這里抽煙嗎？2.could的用法 1)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.那時我們認(rèn)為所說的事不可能是真的。Father said I could swim i

4、n the river.爸爸說我可以在河里游泳。2)表過去的能力I could swim when I was only six.我剛六歲就能游泳。Could在肯定句中表示過去的能力時，常表抽象的一般的能力。He could be very naughty when he was a child.他小時候會是很頑皮的。3)表“允許”。可表示委婉客氣的提出問題或陳述看法Could I use your bike?Yes, you can.他會記得那時嗎?Im afraid I couldnt give you an answer today.恐怕我今天不能回答你。 The teacher sai

5、d you could go to the store for sweets.老師說你可以去商店買糖。3)Could/can+have done 結(jié)構(gòu)表示對過去發(fā)生的事情的“懷疑”或“不肯定”。 could 加完成式還用于肯定句時一般表過去可能完成而卻未完成的動作。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 ea

6、rlier.你本來能早點完成任務(wù)的。（但事實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誤。如表具體做某一件事的能力時，則須用 be able to .He was able to translate the article without a dictionary. 他可以不用詞典翻譯那篇文章。Can表示一貫的能力 ，be able to表示客觀能力和通過努力可以達(dá)到的能力I cant swim. But I am

7、sure I will be able to swim through more practicing.The fire spread through the hotel, but everyone was able to get outWhen the boat sank he was able to swim to the bank3.may 的用法 1)表示請求、可以、允許。You may drive the tractor. 你可以開那臺拖拉機。2)當(dāng)回答由may 引起的問題時，否定答語要用must not,表示“不許可”、“不應(yīng)該”、“不行”。May I come in? Yes,

8、you may.No,you cant No, you may not .No ,you mustntNo ,youd better not.3) may /might 推測性用法 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He might get a job.He may get a job.3 may no 可能不 can not不可能He may not come He cant come3)表建議（

9、可和as well 連用）You may（might）as well stay where you are.你還是原地待著好。（may as well 有“還是的好”的含義）4)表祝愿May you be happy!might 1)表過去的“可能”和“允許”多用于間接引語。She said that he might take her dictionary.她說他可以拿她的詞典去用。除在間接引語中外，might一般不表示過去的“可能”與“許可”。表過去的“可能”可用could，表過去的“許可”可用were (was) allowed to。2)表現(xiàn)在的“可能”，其可能性要比may小。Elec

10、tric irons could be dangerous; they might give you a severe shock.電熨斗會有危險，它可能電著人。3)may (might) + have +done 表示對過去發(fā)生行為的推測，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問題。4.must 的主要用法。1)表示必須、必要We must do everything step by step .我們必須按部就班地做一切事情。Why mus

11、t you always bother me? 為什么你偏要打擾我呢。2)must be + 表語的結(jié)構(gòu)，通常表示猜測，含有“一定”之意。（只用在肯定句中）He must be an honest boy. 他一定是個誠實的男孩。This must be your room. 這一定是你的房間。3)must 的否定式有兩個：當(dāng)回答由must引起的問題時，否定答復(fù)要用neednt或dont have to 表示“不必”、“無須”、“用不著”、“不一定”的意義。當(dāng)表示“不應(yīng)該”、“不許可”、“禁止”時，就用must not。Must I go tomorrow?明天我必須去嗎？Yes, pleas

12、e.是的，請吧！No , you neednt. 不，你不必去。4)must +have +過去分詞的結(jié)構(gòu)，常用在肯定句中，表示對過去發(fā)生行為的推測，含有“一定”、“準(zhǔn)是”的意思。否定和疑問句用can。She must have studied English before.她以前一定學(xué)過英語。5.have to的含義與must是很接近的,只是have to 比較強調(diào)客觀需要，must著重說明主觀看法。I must clean the room.（主觀想法）I have to clean the room.（客觀需要）另外，have to 能用于更多時態(tài)：We had to be there

13、at ten .我們得在十點鐘到那里。We will have to reconsider the whole thing.這一切我們將不得不重新加以考慮。have to 的否定式：dont have to do 表示“不必做”之意。6.ought to 的用法Ought to 后接動詞原形，表義務(wù)，但不及must 那樣具有信心，如：You dont look well. You ought to go to see the doctor.你氣色不好，應(yīng)該去看病。Ought to 用于否定句，其否定形式可縮略為oughtnt ，如：You oughtnt to smoke so much. 你

14、不應(yīng)該抽這么多煙。也可以用于疑問句，如：Ought you to smoke so much?你應(yīng)該抽這樣多煙嗎？Ought to 在間接引語中表過去時形式不變，如：He said you ought to tell the police.他說你應(yīng)該去報告警察。7.shall的用法1)用于第一人稱征求對方的意見，如：What shall I wear on the journey? 我路上穿什么好呢？Shall we dance? 我們跳舞好嗎？2)shall 用于第二、三人稱時表允諾，警告，命令，威脅（現(xiàn)已少見），如：She shall get her share. 她可以得到她的一份。Yo

15、u shall have it back tomorrow.你明天可以將它拿回。情態(tài)動詞should一般不應(yīng)被認(rèn)為是情態(tài)動詞shall的過去式，主要用法有：1)用于第一人稱疑問句中詢問對方的意愿，但語氣較委婉溫和，如：What should we do now? 我們現(xiàn)在該怎么辦？2)表示應(yīng)該、必須，常與must 換用。例如：We should (must) master a foreign language at least.我們應(yīng)當(dāng)至少掌握一門外語。3)“should+be+表語”的結(jié)構(gòu)，表示推測或驚奇。例如：They should be back by now. 他們現(xiàn)在應(yīng)該回來了吧。I

16、 am sorry that she should be so careless. 我感到遺憾她竟會那樣粗心。4)“should+have+過去分詞”的結(jié)構(gòu)，表示過去該做而實際上尚未做的動作或行為；其否定則表示發(fā)生了不應(yīng)該發(fā)生的行為。其同義結(jié)構(gòu)“ought to have +過去分詞”,表示過去“早應(yīng)該”、“本當(dāng)”之意，語氣較強。例如：I should have thought of that. 這一點我是應(yīng)當(dāng)想到的。（但沒想到）They should not have left so soon.他們不應(yīng)當(dāng)走得這么早。（但已走了）5) 在“It is natural (strange, nat

17、ural, necessary, surprised, impossible, important ) that”句型中，主語從句中的謂語動詞要用should +動詞原形”表示“理所當(dāng)然”、“奇怪”、“必要”、“驚異”等的意思。在lest（以免）、for fear (that) (以防)、in case（以備萬一）等之后也要用should+動詞原形;在advise, sugest, order, demand, request 等的從句中should+do”例如：It is necessary that he(should) be sent there at once.有必要馬上派他到那里去。

18、It is strange that he should say so. 他會說這樣的話真是奇怪。Let us go at once lest we should be late for the train.我們馬上走吧，以免趕不上火車。8.will和would的用法1）表示意志，決心或愿望。例如：Surely we will support all the people in the world in their struggle for peace.我們一定要支持全世界人民爭取和平的斗爭。He would not let me try it . 他不肯讓我去試。2）will表示經(jīng)常性、習(xí)慣

19、性、傾向性，would表示過去的習(xí)慣行為。He will sit there hour after hour looking at the traffic go by.他會經(jīng)常一連幾個小時坐在那兒觀看來往的車輛。He would come to see me when he was in Beijing.他在北京時，常來看望我。3）用于第二人稱作主語的疑問句中，表示對對方的請求，would的語氣比will委碗Would/will you kindly tell me the way to the station? 請問到火車站怎么走？4）表可能性This will be the book yo

20、u are looking for.這可能就是你要找的書。She eould be about 60 when she died.他死時大概60歲。9. need和dare的用法 情態(tài)動詞need 實義動詞 need 現(xiàn) You need (not) do You (dont) need to do 在 時 He need (not) do He needs (doesnt need) to do 過 You needed (didnt need) to do 去 時 He needed (didnt need) to do 將 You need (not) do You will (not)

21、 need to do 來 時 He need (not) do He will (not) need to do 句型 時態(tài) 動詞 情態(tài)動詞dare 實義動詞 dare 肯定句 現(xiàn)在時 dare to 少用 dare/dares to do 過去時 dare to 少用 dared to do 否定句 現(xiàn)在時 darent/dare not do do/does not dare (to) do 過去時 dared not do did not dare (to) do 疑問句 現(xiàn)在時 Dare he do? Do you/Does he dear (to) do? 過去時 Dared he

22、 do? Did he dare (to) do neednt have v-ed 表示過去做了某事，但沒有做的必要， 意為“本沒必要”。例如： You neednt have waken me up; I dont have to go to work today10.表推測的情態(tài)動詞句子的反意疑問句He must/may be in the room, isnt he?He cant be in the room, is he？He must have finished the work, hasnt he?He may have done the work last night, did

23、nt he? ：情態(tài)動詞+行為動詞進(jìn)行式 情態(tài)動詞+行為動詞進(jìn)行式（即情態(tài)動詞+ be + v-ing形式），表示推測或評論某動作現(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. 11.情態(tài)動詞+行為動詞完成進(jìn)行式 情態(tài)動詞+行為動詞完成進(jìn)行式（即情態(tài)動詞+ have been + v-ing 形式），表示推測或評論過去某動作是否正在進(jìn)行或一直在進(jìn)行。例如： 1）They should have been meeting to discuss the problem.

24、2）He may / might have been buying stamps in the post office when you saw him.12.used to +v, be used to +v-ing和be used to +v （1）used to +v意為“過去常?！?，“過去一直”；be used to +v-ing / n（名詞）意為“習(xí)慣于”；be used to +v意為“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)?。例如?1）He used to smoke. Now he doesnt

25、. 2）Hes quite used to hard work / working hard. 3）The knife is used to cut bread. 13用作情態(tài)動詞的其他短語 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)動詞。例如： 1）The soldier would sooner die than surrender. 2）The brave soldier would a

26、s 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。對現(xiàn)在和將來的假設(shè)用過去時，對過去的假設(shè)用過去完成時。例如： 1）I would rather you came

27、 on Sunday. 2）I would sooner you hadnt asked me to speak yesterday. 一. 鞏固練習(xí):1. _ you ready? (A)Are (B) Have(C) Will (D) Can2. _ here early? (A)Will he (B) Was he (C)Did he be (D) Were he3.I _ happy about the price of eggs. (A) amt (B) am not (C)do not (D) wont4.Since last year I_ him only once. (A)h

28、ave seen (B) have been seeing (C)see (D) was seeing5.Donald _ sixteen tomorrow. (A)is being (B) going to be (C)shall be (D) will be6.I _ the story at all. (A) dont like(B) like(C)am fond of(D) would like7.I would rather _ than play now. (A) to study(B)am studying(C)study(D) studied8. Id rather you _ anything about it for the time being. (A) do (B) didnt do(C)dont (D) didnt9. The car_much money. (A) not cost(B) not have cost(C)isnt cost(D) didnt cost10. I _ like to eat fi