1、.,1,Unit1 Grammar and Usage,Modal verbs,.,2,一.What are modal verbs?,情態(tài)動詞用在行為動詞前，表示說話人對這一動作或狀態(tài)的態(tài)度，看法或主觀設(shè)想.但本身詞義不完全，不能單獨作謂語，只能和動詞原形一起構(gòu)成謂語。情態(tài)動詞一般沒有人稱和數(shù)的變化。 情態(tài)動詞雖然數(shù)量不多，但用途廣泛，主要有下列： can (could), may (might), must, need, ought to, dare (dared), shall (should), will (would) must not ，have to.,.,3,二. We use

2、 modal verbs to talk about:,1. Ability （能力） 2. Obligation （義務(wù)） 3. Certainty （可能性） 4. Permission （允許）,.,4,.We also use modal verbs to:,5. Make requests（提出請求） 6. Make suggestions（提出建議或意見） 7. Make offers（提供幫助）,.,5,1.Ability(能力）can/could:,1）. can 一般表示與生俱來的能力或者一種客觀可能性,還可以表示請求和允許 。,Learning English _ be d

3、ifficult.,can,Man can not live without air.,_ I use your bike?,Can,.,6,can/could:,2.在疑問句中，用could可表示請求，語氣較委婉。, _I have the television on? Yes, you _. / No, you _,Could,He asks if he _ smoke here.,could,can/may,cant/Im afraid not,.,7,can/could:,3.表示驚異、懷疑、不相信的態(tài)度。（主要用在否定句、疑問句或感嘆句中）,Hes such a nice perso

4、n that he _ commit the crime!,cant,你怎么會如此地粗心！,How can you be so careless!,Can this be true?,.,8,can/could:,4. can never/canttoo表示“無論怎樣也不過分”，“越越好” 。,你過馬路的時候再小心也不為過。,You cant be too careful（/careful enough） while crossing the street.,.,9,Attention:,can/be able to區(qū)別:,Edison always wondered why hens cou

5、ld hatch (孵) chickens while he was not able to.,Question: Are the two modal verbs interchangeable (互換) ? If not, why?,can表示與生俱來的能力或一種客觀可能，而be able to更加強調(diào)通過后天的學(xué)習(xí)和努力獲得的能力，或者在某個客觀的場合和背景下，能做到的事情。,.,10,2.Obligation(義務(wù)）,advisability,necessity,ought to/should,have to,must,Your mother brings you up and take

6、s good care of you, so when she is old, you _ look after her in return.,A.can B.may C.have to D.must,.,11,have to,1.have to 表示一種客觀的需要，即周圍的環(huán)境、狀況等要求或迫使某人不得不做某事。 Its raining outside, so I have to put on my raincoat to go out.,.,12,2. have to 的否定式dont have to，相當(dāng)于neednt，表示沒有義務(wù)或沒必要做某事，意為不必，常用于回答must引導(dǎo)的疑問句

7、。 Must I turn in my homework now? -Yes, you must/ have to. -No, you neednt /dont have to.,.,13,3Certainty(可能性）:,very uncertain,almost certain,might,should,must,may,could,ought to,will,1.He _ be at home.,2.He _ be at home, for he just called me from his home 15 seconds ago.,A.may B.might C.must,A.may

8、 B.might C.must,(can),.,14,must 表示肯定的猜測，譯為“一定”，只能用于肯定句,在疑問句和否定句中表推測時分別要用can/could和cant/couldnt。 This must be your pen. He must be doing his homework now. He cant be in the classroom, for the light has been turned off.,must,.,15,must,2. 表示“堅持”（常用于固定句型：if you must do sth. 如果你非得要做某事）,如果你真的要走，那就悄悄離開。,If

9、 you must leave, do it quietly.,.,16,3.must 做必須講時，其疑問句的否定回答用neednt，表示不必，mustnt表示不準(zhǔn)，禁止。 -Must I work out the problem tonight? -No, you neednt. Its my car. You mustnt use it without my permission.,.,17,4.Permission(允許）may/might:,1. 表示許可，常譯為可以。表示請求、允許時，might比may的語氣更委婉一些。,-Might/May I use your computer?

10、 - Yes, you can. /No, you cant/mustnt.,.,18,may/might:,2.用于祈使句中表示祝愿。,3.表示推測、可能（只用于肯定句，疑問句則要用can或could）。,祝你成功！,May you succeed.,He may be very busy now.,May you be happy all your life.,.,19,4. may/might as well. 還是.為好，不妨 Its very late,so you may/might as well go t bed.,.,20,5.Making requests (提出要求):,

11、Can you help me with my training?,I dont know how to use this equipment!,will can could would,informal,formal,.,21,will/would:,1. 表示請求、建議等，用于第二人稱疑問句中，would比will委婉客氣。,sentence pattern,Would you please,Would you mind,Would rather,Would you like,.,22,will/would:,2.表示意志、愿望和決心。有愿意，要的意思，will指現(xiàn)在，would指過去的習(xí)

12、慣性動作或傾向。,I will never do that again. I would go there with you.,.,23,will/would:,3.可表示經(jīng)常性、習(xí)慣性、傾向性。翻譯為“經(jīng)常、慣于、總是”。,The old man _have a smoke under a big tree every afternoon after he finished his farm work.,would,.,24,6.Making suggestions (提出建議): Shall(可以）/should(應(yīng)該） 、Ought to (應(yīng)該）/had better（最好),.,25

13、,shall:,1.Shall用于第一、第三人稱疑問句中，表示說話人征求對方的意見、向?qū)Ψ秸埵净蛱峁椭?。,1.Shall we begin our lesson? 2.When shall he be allowed to leave hospital? 3.Shall I carry this bag for you?,.,26,shall:,2.Shall用于第二、第三人稱，表示說話人給對方命令、警告、允諾或威脅。,You shall fail if you dont work harder. He shall be punished according to the rule. 等我

14、讀完這本書，就會給他的。,He shall have the book when I finish it.,警告,威脅,允諾,.,27,should:,1.Should表示勸告、建議、命令，其同義詞是ought to；在疑問句中，通常用should代替oughtto。,Should I open the window?,我們應(yīng)當(dāng)要相互學(xué)習(xí)。,We should learn from each other.,.,28,should:,2.情態(tài)動詞should用于第一人稱時可以表示說話人的一種謙遜、客氣、委婉的語氣。,I should advise you not to do that again

15、.,.,29,3. should表示意外或驚訝 常譯為 “居然，竟然”。 I cant believe such a gentleman should be so rude to the old. 我不敢相信這樣一個紳士居然對老人如此無禮。,should:,.,30,4. should 表示猜測時，一般指按經(jīng)驗或邏輯判斷，翻譯成“照說應(yīng)該，估計，想必”,should:,-When can I come for the photos ? I need them tomorrow afternoon. -They should be ready by 12 : 00 .,.,31,7.Making

16、 offers (提供幫助):,Dont worry, dear, I will wash them right away.,Mom, my dirty clothes have been piled up! I dont have time,.,32,三、情態(tài)動詞+不定式完成式是歷年高考的熱點之一，可表示“推測”、“責(zé)備”、“懷疑”等多種意義。 1. must have done 肯定做了 2. may/might have done 可能已做了 3. cant/ couldnt have done不可能做了 4. should /ought to have done本該做但沒做 5. sh

17、oudnt/oughtnt to have done本不該做但做了 6. could have done 本可以做但沒做 7.neednt have done 本不必做但做了 8. would rather have done 本想做但沒做,.,33,I could have come here earlier. But my car broke down. I should have arrived at noon but my train was delayed. I neednt have bought so much wine- only five people come here.,.,34,四. 可兼做行為動詞的情態(tài)動詞：need 、 dare,情態(tài)動詞 (+動詞原形),行為動詞,need,dare,1.無人稱和數(shù)的變化;,2.尤其用于：,*否定句及疑問句中;,*在if/whether之后;,*或與hardly, never, no one, nobody連用;,3.常以neednt 和darent 的形式出現(xiàn);,4.dare有其過去時dared.,多用于肯定句; (sb.) need to do dare to do (sth.