情態(tài)動詞的定義

1、情態(tài)動詞的定義情態(tài)動詞的定義：情態(tài)動詞是一種本身有一定的詞義，表示說話人的情緒，態(tài)度或語氣的動詞，但不能單獨作謂語，只能和其他動詞原形 構成謂語。We can be there on time tomorrow.我們明天能按時去那兒。May I have your name?我能知道你的名字嗎？Shall we begin now?我們現(xiàn)在就開始嗎？You must obey the school rules.你必須遵守校規(guī)。情態(tài)動詞數(shù)量不多，但用途廣泛，主要有下列： can (could), may (might), must, need, oughtto, dare (dared), sh

2、all (should), will (would).情態(tài)動詞的位置：情態(tài)動詞在句中放在謂語動詞之前，謂語動詞前若有助動 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?你要什么？How dare you treat us like that !你怎能那樣對待我們！情態(tài)動詞的特點：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

3、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。He could be here soon.他很快就來。We can't carry the heavy box.我們搬不動那箱子。rm sorry I can't help you.對不起，我?guī)筒簧夏?。情態(tài)動詞的用法：1 can (could)表示說話人能，可以，同意，準許，以及 客觀條件許可，could 為 can 的過去式。Can you pass me the books?你能給我遞一下書嗎？Could you help me, please?請問,你能幫助我嗎？What can y

4、ou do?你能干點什么呢？Can you be sure?你有把握嗎？can和could只能用于現(xiàn)在式和過去式兩種時態(tài)，將來時態(tài)用be able to來表示。He could help us at all.他完全可以幫助我們。With the teacher's help,I shall be able to speak English correctly.由于老師的幫助，我將能準確地講英語。2 may (might) 可以，表示說話人同意，許可或請求 對方許可。You may take the book home.你可以把書帶回家去.May I come in?我可以進來嗎？May

5、 I use your dictionary?我可以用你的詞典嗎？You may put on more clothes.你可以多穿點衣服.He said he might lend us some money.他說他可以借給我們一些錢。mayn't.一種表示客氣或對may否定式為 may not,縮寫形式是might 是may 的過去式，有兩種用法 過去式，一種表示虛擬語氣，使語氣更加委婉 可能性的懷疑。He told me he might be here on time.他說他能按時間來。Might I borrow some money now.我可以借點錢嗎？He might

6、 be alive.他可能還活著。havemust用來指一般現(xiàn)在時和一般將來時，過去式可用 to的過去式代替。I must finish my work today.我今天必須完成我的工作。You mustn't work all the time.你不能老是工作。Must I return the book tomorrow?我必須明天還書嗎？After such a long walk, you must be tired.走了這么長的路，你一定困了。He must be the man I am looking for.他一定是我要找的人。He had to go because

7、 of somebody's callinghim that day.那天他要走是因為有人叫他must + have +過去分詞，表示現(xiàn)在對過去事物的推測。He must have told my parents about it.他一定把這件事情告訴我父母親了。He must have received my letter now.他現(xiàn)在一定收到我的信了。It's six o'clock already, we must have been late again.已經(jīng)六點鐘了，我們一定又遲到了。must 和have to 的區(qū)別：must表示說話人的主觀思想 have

8、 to 表示客觀需要。You must do it now.你必需現(xiàn)在就干。（說話人認為必須現(xiàn)在干）I have to go now.我得走了。（客觀條件必須現(xiàn)在走）4 need需要 多用在否定式或疑問句中.Need I attend the meeting tomorrow?我需要明天參加會議嗎？You need not hand in the paper this week.這一周你不必交論文。need是一個情態(tài)動詞，他的用法完全和其他情態(tài)動詞一 樣，但need還可當作實義動詞使用，這時need就象其他 動詞一樣,有第三人稱，單復數(shù)，后面加帶to的動詞等特性。I need a bike t

9、o go to school.我上學需要一輛自行車。Do you need a dictionary?你需要詞典嗎？She needs a necklace.她需要一條項鏈。needn't + have + 過去分詞 表示過去做了沒必要做的 事情。You needn't have taken it seriously.這件事情你不必太認真。5 dare 敢 多用在否定或疑問句中。The little girl dare not speak in public.小女孩不敢在公眾面前說話。Dare you catch the little cat?你敢抓小貓嗎？dare除用作情態(tài)動

10、詞外，更多的是當實義動詞使用，用法 同實義動詞一樣，要考慮人稱，單復數(shù),時態(tài)等。Do you dare to walk in the dark?你敢黑夜走路嗎？He doesn't dare to tell the teacher what happenedthat day.他不敢告訴老師那天發(fā)生的事。6 ought 應當,應該后面跟帶有to的動詞不定式。You ought to read these books if you want to knowhow to repair the motorcar.如果你想知道如何修理汽車，你應該讀這些書。You ought to bring t

11、he child here.你應該把孩子帶來。ought + to have done句型。指過去動作，表示一件事情該做而未做。You ought to have been here yesterday.你昨天就應該來。ought not to have done句型。表示一件不該做的事情卻做了。You ought not to have taken the book out of the reading-room.你不應該把書帶出閱覽室。7 will (would) 決心,愿望。 would 為will的過去式，可用于各人稱。r II do my best to catch up with

12、them.我要盡全力趕上他們。r II never do it again, that's the last time.我再不會做那件事情了 ，這是最后一次。He said he would help me.他說他會幫助我。will, would用于疑問句表示說話人向對方提出請求或詢問,用would 比will更婉轉，客氣。It's hot. Will you open the windows?天氣太熱了，你能打開窗戶嗎？Will you help me to work it out?你能幫我解這道題嗎？Would you like some coffee ？給你來點咖啡怎樣？

13、8 Shall, should表示命令,警告,允諾,征求,勸告,建議驚奇。You should hand in the exercise book.你應該交作業(yè)本兒了。This should be no problem.這應該沒問題。Shall we go now.我們現(xiàn)在可以走了嗎？Why should I meet him ？為什么我要見他？9 have to,不得不,必須,表示客觀條件只能如此 must則表示主觀思想必須。I have to go now.我現(xiàn)在得走了。I have to cook for my child.我得給孩子做飯。You must be here on time

14、 next time.你下次一定要按時來。We must go to get the timetable ourselves.高考常見語法一虛擬語氣一.語氣的定義和種類。1 語氣(mood)語氣是動詞的一種形式，表示說話人對某一行為或事情的看 法和態(tài)度。2語氣的種類a. 陳述語氣：表示動作或狀態(tài)是現(xiàn)實的、確定的或符合事實的，用于陳述句、疑問句和某些感嘆句。如：There are two sides to every question.每個問題都有兩個方面。Were you busy all day yesterday? 昨天一整天你都很忙 嗎？How good a teacher she is

15、!她是多好的一位老師啊！b. 祈使語氣：表示說話人對對方的請求或命令。如：Never be late again!再也不要遲到了。Don ' t forget to turn off the light. 別忘了關燈。c. 虛擬語氣：表示動作或狀態(tài)不是客觀存在的事實，而是說 話人的主觀愿望、假設或推測等。如：If I were a bird, I could fly in the air.如果我是一只小鳥，我就能在空中飛行。I wish I could pass the examination. 我希望我能通過考 試。May you succeed!祝您成功！.虛擬語氣在條件從句中的用

16、法 條件從句有兩類，一是真實條件句，另一是虛擬條件句。如 果假設的情況可能發(fā)生，是真實條件句，這種情況下謂語用 陳述語氣。如：If time permits, we ' go fishing together.如果時間允許，我們就一起去釣魚。如果假設的情況是不存在的或不大可能發(fā)生的，則是虛擬條件句。如：If you had come yesterday, you would have met thatfamous professor.如果你昨天來，你就會見到那位著名的 教授了。（隱含的事實是：你昨天沒來，也沒見到那位著名 教授）。在含有虛擬條件句的復合句中，主從句的謂語都要用虛擬語 氣

17、，現(xiàn)將其形式列表如下： 動詞形式時間從句主句 與現(xiàn)在事實相反動詞過去式（be 的過去式用動詞原形動詞過去分詞過去分詞were)would(could/should/might)+與過去事實相反 had+would(could/should/might)+have與將來事實可能相反動詞過去式should+動詞原形動詞原were to+ 動詞原形 would(could/should/might)+形注：主句中的should只用于第一人稱，但在美國英語中， should 常被 would 代替；從句中的 should 可用于各種人 稱。1.表示與現(xiàn)在事實相反的假設和結果。如：If I were y

18、ou, I should(would ,could, might)tell him the truth.要是我是你，我就會告訴他真相了。(事實上我 不是你)If she had time, she would(could, might)help me.女口果她有時間，她就會幫我了。(事實上她沒有時間)2表示與過去事實相反的假設和結果。如：If I had known your telephone number yesterday, I should(would, could, might)have telephoned you.女口果昨天我知道了你的電話號碼，我就會給你打電話了。(事實 上我昨

19、天不知道你的電話號碼。)If you had taken my advice, you wouldn' t(couldn ' t)have failed in the exam. 如果你聽了我的建議， 你就不會考 試不及格。(事實上你根本沒聽我的。3表示與將來事實可能相反的假設和結果。如：If it should rain, the crops would(could, might)be saved.假如天下雨，莊稼可能就收獲了。-What would happen if I put the paper on the fire?-It would burn.-我若把只放在火上會

20、怎么樣？-紙會燒著。注：在表示與將來事實可能相反的條件從句中，were to + 動詞原形比較正式，常用于書面語中。如：If you were to go to Beijing, you would (could, might)have a chance to visit Tian An Men Square.三.虛擬語氣的其它用法。1虛擬語氣在主語從句中的用法。在 “ It is important (strange, natural, necessary)that ”這類句型中，that所引導的主語從句中的謂語動詞常用“ (should)+動詞原形”結構，表示某事是“重要”，“奇怪”，“自

21、然”，“必要”等意義。如：It is important that every Beijinger (should) be able tospeak English.重要的是每個北京人能說英語。It is necessary that he (should) be sent to hospital atonce.有必要馬上把他送醫(yī)院。2虛擬語氣在賓語從句中的用法。(1) 在動詞wish后的賓語從句中，表示與現(xiàn)在或過去的事 實相反，或對將來的主觀愿望，從句通常省略連詞that oa. 表示對現(xiàn)在情況的虛擬：從句動詞用過去式或過去進行式(be的過去式用 were )表示。如：I wish I kn

22、ew the answer to the question.我希望知道這個問題的答案。(可惜不知道。)I wish it were spring in my hometown all the yeararound .但愿我的家鄉(xiāng)四季如春。(只是愿望，實際根本不 可能實現(xiàn)。)b. 表示對過去情況的虛擬： 從句動詞用had+過去分詞。如:I wish （that） I hadn ' t wasted so much time.我后悔不該浪費這么多時間。（實際上已經(jīng)浪費掉了。）He wishes （wished） he hadn ' t lost the chance.他真希望沒有失

23、去機會。（事實上機會已經(jīng)失去了，他感到惋惜。）c. 表示對將來的主觀愿望：謂語動詞形式為“would/should/could/might+動詞原形”，此時要注意，主句的主語與從句的主語不能相同，因為主句的主語所期望 的從句動作能否實現(xiàn)，取決于從句主語的態(tài)度或意愿（非動 作名詞除外）。如：但愿雨能停止。我希望你安靜一些。,demand（ 要求）,order（命令）,I wish it would stop raining.I wish you would be quiet.（2 ）在 suggest（建議）propose（ 建議）,insist （堅持要做），command（ 命令）,requ

24、est（要求）,desire（希望）等動詞后的賓語從句中，謂語動 詞用“ （should）+動詞原形”，表示建議，要求，命令等。如:I suggest that we （should） start the meeting at once.我建議馬上開會。The undergraduate insisted that he （should） go to work inthe south.這位即將畢業(yè)的學生堅持要到南方去工作。注： 當 suggest 表示暗示，主語為 something ； insist 表 示堅持觀點時，后接的賓語從句當用真實語氣。比較：His silence suggeste

25、d that he agreed with mydecision.他的沉默暗示著他贊成我的決定。He suggested that I (should) stick to mydecision.他建議我堅持自己的決定。He insists that doing morning exercises does good topeople ' s health.他堅持認為做早操對健康有益。He insists that he (should) do morning exercises everyday.他堅持他每天都要早操3虛擬語氣在表語從句中的用法。當主語為 advice, suggest

26、ion, order, proposal 等詞時后 接表語從句，表語從句中的謂語動詞常用“(should)+動詞原形”結構，表示某人建議、勸告、命令等的內容。如：My advice is that you should practise speaking Englishasoften as possible.我的建議是你盡可能經(jīng)常地練習說英語。The order from the commander was that the troops shouldset off for the front immediately.司令官的命令是部隊立即開拔去前線。4 .特殊的虛擬語氣結構。(1 )虛擬語氣

27、用在狀語從句中由as if或as , though引導的狀語從句表示比較或方式時，從句中的謂語動詞用虛擬語氣。動詞形式用動詞的過去式(be f were)或had+過去分詞。如：The teacher treats the student as if he were her ownchild.這位老師帶這位學生就象她的親生孩子一樣。He speaks as if he had been to the UnitedStates.他說得好象他真的到過美國似的。(2) 在 It is time (that) ；I' d rather (that)句型中從句的謂語動詞常用動詞的過去式表示虛擬語

28、氣，意思是“該干 某事了，時間已經(jīng)有些晚了”“我寧愿/希望”。如：It is time that we did something to stoppollution.該我們做些什么制止污染的時候了。It is time that Father picked up Lily from thekindergarten.該父親去幼兒園接莉莉的時候了。I' d rather you told me the truth.我真希望你告訴我真相。I' d rather I didn ' t see you again. 我寧愿不再見著你。(3 )虛擬語氣用在簡單句中a情態(tài)動詞的過去式

29、用于現(xiàn)在時態(tài)時，表示說話人的謙虛、 客氣、有禮貌、或委婉的語氣，常用于日常會話中。如：Would you be kind enough to show me the way to the postoffice?請你告訴我去郵局的路好嗎？It would be better for you not to stay up toolate .你最好別熬夜到很晚。b在一些習慣表達中。如：You ' d better set off now.你最好現(xiàn)在就出發(fā)。I' d rather not tell you the secret.我情愿不告訴你這個秘密。c用“ may+動詞原形”表示祝愿

30、，但愿，此時may須置于句首(多用于正式文體中)。如：May good luck be yours!祝你好運！May you be happy!祝你快樂！May you do even better!祝你取得更大成就！用動詞原形。例如：Long live the people!人民萬歲！“God bless you, ” said the priest. 牧師說：“愿上帝保佑 你！”5 .虛擬語氣在同位語從句中的用法在名詞 advice, suggestion, order, proposal 等后接的同位語從句中，謂語動詞用虛擬語氣，起形式為“ (should)+動詞原形”，說明“建議”，“

31、勸告”，“命令”等的具體內 容。如：The order came that the work should be finished twodaysahead of time.提前兩天完成工作的命令傳來了。Reluctantly she accepted their proposal that she should beoperated on.她勉強接受了他們要她去接受手術的建議。（一）主從句時間不一致情況下的虛擬語氣（混合條件句）（二）有時條件從句中的動作和結果與主句中的動作，發(fā)生的時間不一致，這時動作的形式應根據(jù)它所表示的時間加 以調整。如：If you had followed my ad

32、vice, you would be able to finishthe work now.如果你當時聽了我的話，現(xiàn)在就能完成這份工作了。（從句說明過去，主句說明現(xiàn)在。）If I were you, I would have gone to her birthdayparty.如果我是你，我就去參加她的生日晚會了。（從句說 明現(xiàn)在，主句說明過去。）If you hadn ' t lent me some money, I couldn' t haveboughtthe new house and most likely I would be still living inthe

33、dangerous house now.假若你不借錢給我，我不可能買下這幢新房，很可能現(xiàn)在還住在危房里。（從句 說明過去，主句說明過去和現(xiàn)在。）（二）含蓄條件句 非真實條件句中的條件從句有時不表出來，只暗含在上下文 中，這種句子叫做含蓄條件句。含蓄條件句大體有三種情況；1. 條件暗含在短語中。如：(1) W hat would I have done without you?如沒有你，我會怎么辦呢？(條件暗含在分詞短語withoutyou 中)(2) It would be easier to do it this way.這樣做會比較容易。(條件暗含在不定式短語to do it thiswa

34、y 中)(3) This same thing, happening in wartime, would leadtoa disaster. 同樣的事，如發(fā)生在戰(zhàn)時，就會釀成大禍。(條件暗含在分詞短語happening inwartime 中)(4) But for your help we couldn' t have succeeded intheexperiment.如果沒有你的幫助，我們的實驗是不會成功。(暗含條件是 but for your help)(5) He must have the strength of a hippopotamus, orhenever coul

35、d have vanquished that great beast.他一定是力大如河馬，否則他絕不會擊敗那只龐大的野獸。(暗含條件是連詞 or)(6) Alone, he would have been terrified.如是單獨一人，他是會感到害怕的。(暗含條件是alone)2. 條件暗含在上下文中。如：(7) You might stay her forever.你可以永遠待在這兒。(可能暗含if you wantedto)(8) We would have succeeded.我們本來是會成功的。（可能暗含 if we had kepttrying)(9) Your reputati

36、on wouldbe ruined.你的名譽會敗壞的。（可能暗含if youshould accept it)(10) I would appreciate a little of your time.謝謝你給我一點時間吧。(可能暗含if you were so kind asto give me a little ofyour time)3. 在不少情況下，虛擬式已變成習慣說法，很難找出其暗含的條件。如：(11) You wouldn ' t know.你不會知道。(12) I would like to come.我愿意來。(13) I wouldn ' t have dr

37、eamed of it.這是我做夢也不會想到的。(14) He told the story in such minute detail that he mighthimself have been an eye-witness.他將那事講的非常仔細，簡直就象他親眼看見一樣。（三）條件從句中省去if的情況在if引導的表示虛擬的條件狀語從句中，?？梢允÷詉f,將had, were 或 should 提至句首。如：Had I seen the film, I would have discussed it with themlast night.假如我看了那部電影，昨晚我就可以和他們一起討論了。W

38、ere I a bird, I could fly freely.假如我是一只小鳥，我就能自由翱翔。Should it rain next week the farmers would have a goodharvest.要是下周能下雨的話，農民們就能有個好收成了。put off.her child?1 He suggested that the meetingA. not beB. should notC. wouldn ' tD. be not2 What would have happened if youA. hadn ' t helpedC. wouldn '

39、; t help3 It is strange that heA. thinksC. thoughtB. couldn ' t helpD. didn ' t helpso.B. thinkD. will thinkwith her now.4 If Iwith her last summer, IB. had workedC. had workedD. had workedwill get on very well5 I wish Imy uncle yesterday.A. metB. have metC. would meetD. had met6 The oldprof

40、essorgave orders that theA. worked am getting on very wellwouldget on very wellwould have got on very wellexperimentbefore 6.A. was finishedB. will finishC. be finishedD. shall be finished7 It' s high time hehome.A. goesB. wentC. will goD. is going to goyou succeed andyou be healthy.A. May - -mayB. Wish wishC Hope -hopeD.