不定式的定義

1、不定式的定義在語法中，1是動詞的一種不帶詞形變化從而不指示人稱、數(shù)量、時態(tài)的形式。它被叫做不定式，是因為動詞不被限定，或者說不被詞形變化所局限。 動詞不定式指由to 加上動詞原形（而且只能是動詞原形）所構(gòu)成的一種非限定性動詞，但在有些情況下to可以省略。動詞不定式在語法功能上可作主語 、賓語、表語、定語和狀語。 動詞不定式的構(gòu)成與形式動詞不定式可以作以上各種成分，但它畢竟是動詞，所以有動詞的屬性。 動詞不定式及其短語還可以有自己的賓語、狀語，雖然動詞不定式在語法上沒有表面上的直接主語，但它表達的意義是動作，這一動作一定由使動者發(fā)出。這一使動者我們稱之為邏輯主語，其形式如下： 時態(tài)主動形式被動形

2、式一般式（not）to do（not）to be done完成式（not）to have done （not）to have been done進行式（not）to be doing完成進行式（not）to have been doing1) 一般式：一般現(xiàn)在時表示的動詞，有時與謂語動詞表示的動作同時發(fā)生，有時發(fā)生在謂語動詞的動作之后。 He seems to know this.他好像知道這。 I hope to see you again. = I hope that I'll see you again.我希望再見到你。 2) 完成式：表示的動作發(fā)生在謂語動詞表示的動作之前。 I

3、'm sorry to have given you so much trouble. 很抱歉給你添了這么多麻煩。 He seems to have caught a cold. 他似乎感冒了。 3) 進行式：表示動作正在進行，與謂語動詞表示的動作同時發(fā)生。 He seems to be eating something.他似乎在吃東西。 4) 完成進行式： She is known to have been wreaking on the problem for many years.她知道已處于這個問題很多年了。 不定式在句中的成分一、作賓語1）動詞+ 不定式afford,aim,

4、appear,agree,arrange,ask,be,decide,bother,care,choose,come,dare,demand,desire,determine,expect,elect,endeavor,hope,fail,happen,help,hesitate,learn,long,mean,manage,offer,ought,plan,prepare,pretend,promise,refuse,seem,tend,wait,wish. The driver failed to see the other car in time. 司機沒能及時看見另一輛車。 I hap

5、pen to know the answer to your question. 我碰巧知道你那道問題的答案。 2）動詞+賓語+不定式 ask, beg, choose, expect , hate, help intend like, love, need prefer, prepare, promise, want, wish 例句： a.I like to keep everything clean. 我喜歡每件東西都保持整潔。 b.I like you to keep everything clean. 我喜歡你能使每件東西都保持整潔。 c.I want to talk to Tom.

6、 我想和湯姆談話。 d.I want you to talk to Tom. 我想讓你和湯姆談話。 3）動詞+疑問詞+ 不定式 decide, know, consider forget, learn, remember, show, understand, see, wonder, hear, find out, explain, tell 例句： a.Please show us how to do that. 請演示給我們?nèi)绾稳プ觥?b.There are so many kinds of tape-recorders on sale that I can't make up m

7、y mind which to buy. 有這么多的錄音機，我都拿不定主意買哪一種。 c.The question is how to put it into practice. 問題是怎樣把它付諸實施。 （注意：疑問詞帶不定式在句中作成分時，謂語動詞用單數(shù)。） 二、作補語1) 動詞+賓語+不定式(to do) advise,allow,appoint,believe,cause,challenge,command,compel,consider,declare,drive,enable,encourage,find,forbid,force,guess,hire,imagine,impel,

8、induce,inform,instruct,invite,judge,know,like,order,permit,persuade,remi-nd,report,request,require,select,send,state,suppose,tell,think,train,trust,understand,urge,warn 例句： a.Father will not allow us to play on the street. 父親不讓我們在街上玩耍。 b.We believe him to be guilty. 我們相信他是有罪的。 Find 的特殊用法： Find 后可用分詞

9、做賓補，或先加形式賓語，再加形容詞，最后加帶to 的動詞不定式。find后也可帶一個從句。此類動詞還有g(shù)et，have。 例句： a.I found him lying on the ground. b.I found it important to learn. c.I found that to learn English is important. 典型例題: The next morning she found the man _ in bed，dead. A. lyingB. lieC. layD. laying 答案：A.find的賓語后面，用分詞或分詞短語，起賓語補足語作用?，F(xiàn)在

10、分詞表達主動，也表達正在進行，過去分詞表達被動。 2) to + be 的不定式結(jié)構(gòu)，作補語的動詞 Acknowledge,believe,consider,think,declare(聲稱),discover,fancy(設(shè)想),feel,find,guess,judge,imagine,know,prove,see(理解),show,suppose,take(以為),understand 例句： a.We consider Tom to be one of the best students in our class. 我們認為湯姆是班上最好的學(xué)生之一。 典型例題 Charles Babb

11、age is generally considered_ the first computer. A. to inventB. inventingC. to have inventedD. having invented 答案：A. 由consider to dosth. 排除B、D。. 此句只說明發(fā)明這一個事實，不定式后用原形即可。而C為現(xiàn)在完成時，發(fā)明為點動詞一般不用完成時，且此處也不強調(diào)對現(xiàn)在的影響，因此不選C。 3) to be +形容詞 Seem,appear,be said,be supposed,be believed,be thought,be known,be reporte

12、d,hope, wish,desire,want,plan,expect,mean 例句： a.The book is believed to be uninteresting. 人們認為這本書沒什么意思。 4)there be+不定式 believe,expect,intend,like,love,mean,prefer,want,wish,undrstand 例句： a.We didn't expect there to be so many people there. 我們沒料到會有那么多人在哪里。 有些動詞需用as 短語做補語，如regard, think believe, t

13、ake, consider. We regard Tom as our best teacher.我們認為湯姆是我們最好的老師。 Mary took him as her father .瑪麗把他當(dāng)作自己的父親。 三、作主語easy,difficult,hard,important,possible,impossible,comfortable,necessary,better; the first,the next,the last,the best,too much,too little,not enough,Kind,nice,stupid,rude,clever,foolish,tho

14、ughtful,thoughtless,brave,considerate,silly,elfish 例句： a.It's easy (for me) to do that. 我做這事太容易了 b.It's so nice to hear your voice. 聽到你的聲音真高興。 b.It's necessary for you to lock the car when you do not use it. 當(dāng)你不用車的時候，鎖車是有必要的。 c.It's very kind of him to help us. 他幫助我們，他真好。 d.It was si

15、lly of us to believe him. 我們真愚蠢，竟然相信了他。 e.It seemed selfish of him not to give them anything. 他不給他們?nèi)魏螙|西，這顯得太自私了。 注意： 1) 其他系動詞如，look，appear等也可用于此句型。 2) 不定式作為句子成分時，動詞用單數(shù)形式。 3) 當(dāng)不定式作主語的句子中又有一個不定式作表語時，不能用It is to的句型 (對)To see is to believe.百聞不如一見。 (錯)It is to believe to see. 四、作表語不定式可以在句中作表語，起名詞的作用。 例如：

16、My work is to clean the room every day. His dream is to be a doctor. 五、作定語不定式作表語表示具體動作或?qū)韯幼?；動名詞作表語表示抽象的一般行為。 To be kind to the enemy is to be cruel to the people. My chief purpose is to point out the difficulties ofthe matter. What I would suggest is to put off the meeting. 當(dāng)主語和表語都是不定式時，其含義一是條件，一是結(jié)果

17、 （例）。當(dāng)主語是aim,duty,hope,idea,mista ke,plan,purpose,suggestion等為中心詞的名詞詞組 （例）時，或以what引導(dǎo)的名詞性分句 （例），不定 式說明主語的內(nèi)容。 （例）Our work is serving the people. （例）What he likes is taking a walk after supper. （例）The story told by Mr.Wang is interesting. 句動名詞作表語，與主語部分可以轉(zhuǎn)換，如Serving thepeople is out work,而句中是現(xiàn)在分詞作表語，說明主

18、語的性質(zhì)、狀態(tài)，現(xiàn)在分詞具有形容詞的各種特征，另外，動名詞作表語還應(yīng)與進行時態(tài)區(qū)別開來。 六、作狀語1）目的狀語 To only to,in order to,so as to, so (such) as to 例句： He ran so fast as to catch the first bus. 他飛快地跑以便趕上第一班車。 I come here only to say good-bye to you. 我來僅僅是向你告別。 2）作結(jié)果狀語，表事先沒有預(yù)料到的，要放在句子后面。 What have I said to make you angry. He searched the ro

19、om only to find nothing. 3）表原因 I'm glad to see you. 典型例題 The chair looks rather hard, but in fact it is very comfortable to _. A. sitB. sit onC. be seatD. be sat on 答案：B.如果不定式為不及物動詞，其后應(yīng)有必要的介詞。當(dāng)動詞與介詞連用時，常位于"形容詞+動詞不定式"結(jié)構(gòu)的末尾。 不定式的特殊句型1、so as to 1） 表示目的；它的否定式是so as not to do。 Tom kept quie

20、t about the accident so as not to lose his job. 湯姆對事故保持沉默是為了不丟掉他的工作。 Go in quietly so as not to wake the baby. 輕點進去，別驚醒了嬰兒。 2)so kind as to -勞駕 Would you be so kind as to tell me the time? 勞駕，現(xiàn)在幾點了。 2、 "Why not +動詞原形"表達向某人提出建議 "為什么不?" "干嗎不?" 例如： Why not take a holiday?

21、干嗎不去度假? 3、It's for sb.和 It's of sb. 1）for sb. 常用于表示事物的特征特點，表示客觀形式的形容詞，如easy, hard, difficult,interesting, impossible等： It's very hard for him to study two languages. 對他來說學(xué)兩門外語是很難的。 2）of sb的句型一般用表示人物的性格，品德，表示主觀感情或態(tài)度的形容詞，如good, kind, nice, clever, foolish, right。 It's very nice of you

22、to help me. 你來幫助我，你真是太好了。 for 與of 的辨別方法： 用介詞后面的代詞作主語，用介詞前邊的形容詞作表語，造個句子。如果道理上通順用of，不通則用for。如： You are nice.(通順，所以應(yīng)用of)。 He is hard.(人是困難的，不通，因此應(yīng)用for。) 4、不定式的特殊句型tooto 1）tooto太以至于 He is too excited to speak. 他太激動了，說不出話來。 - Can I help you ? 需要我?guī)兔? - Well, I'm afraid the box is too heavy for you to

23、 carry it, but thank you all the same.不用了。這箱子太重，恐怕你搬不動。謝謝您。 2) 如在too前有否定詞，則整個句子用否定詞表達肯定， too 后那個詞表達一種委婉含義，意 為"不太"。 It's never too late to mend.(諺語) 改過不嫌晚。（亡羊補牢，為時不晚） 3)當(dāng)too 前面有only, all, but時，意思是：非常 等于very。 I'm only too pleased to be able to help you. 我非常高興能幫助你。 He was but too eage

24、r to get home. 他非常想回家。1） 動名詞與不定式的區(qū)別： 動名詞表達的是： 狀態(tài)，性質(zhì)，心境，抽象，經(jīng)常性，已發(fā)生的不定式表達的是： 目的，結(jié)果，原因，具體，一次性，將發(fā)生的 2）接不定式或動名詞，意義相同。 3）動名詞與不定式語義不同的有11 組： 1 stop to dostop doing 2 forget to doforget doing 3 remember to doremember doing 4 regret to doregret doing 5 cease to docease doing 6 try to dotry doing 7 go on to d

25、ogo on doing 8 afraid to doafraid doing 9 interested to dointerested doing 10 mean to domean doing 11 begin/ start to dobegin/ start doing 1 forget doing/to do forget to do忘記要去做某事。(未做) forget doing忘記做過某事。(已做) The light in the office is stil on. He forgot to turn it off. 辦公室的燈還在亮著，它忘記關(guān)了。(沒有做關(guān)燈的動作) He

26、 forgot turning the light off. 他忘記他已經(jīng)關(guān)了燈了。( 已做過關(guān)燈的動作) Don't forget to come tomorrow. 別忘了明天來。(to come動作未做) 典型例題 - The light in the office is still on. - Oh，I forgot_. A. turning it offB. turn it offC. to turn it offD. having turned it off 答案：C。由the light is still on 可知燈亮著，即關(guān)燈的動作沒有發(fā)生，因此用forget to

27、do sth. 而forget doing sth表示燈已經(jīng)關(guān)上了，而自己忘記了這一事實。此處不符合題意。 2 stop doing/to do stop to do停止，中斷做某事后去做另一件事。 stop doing停止做某事。 They stop to smoke a cigarette.他們停下來，抽了根煙。 I must stop smoking.我必須戒煙了。 典型例題 She reached the top of the hill and stopped _on a big rock by the side of the path. A. to have restedB. res

28、tingC. to restD. rest 答案：C。由題意可知，她到了山頂，停下來在一個路邊的大石頭上休息。因此，應(yīng)選擇"stop to do sth. 停下來去做另一件事"。而不僅僅是爬山動作的終止，所以stop doing sth.不正確。 3 remember doing/to do remember to do 記得去做某事(未做) remember doing記得做過某事(已做) Remember to go to the post office after school. 記著放學(xué)后去趟郵局。 Don't you remember seeing the

29、 man before? 你不記得以前見過那個人嗎? 4 regret doing/to do regret to do對要做的事遺憾。(未做) regret doing對做過的事遺憾、后悔。(已做) I regret to have to do this, but I have no choice. 我很遺憾必須這樣去做，我實在沒有辦法。 I don't regret telling her what I thought. 我不為告訴她我的想法而后悔。 典型例題 -You were brave enough to raise objections at the meeting. -W

30、ell, now I regret _ that. A. to doB. to be doingC.to have doneD.having done 答案：D。regret having done sth. 對已發(fā)生的事感到遺憾。regret to do sth. 對將要做的事感到遺憾。本題為對已說的話感到后悔，因此選D。 5 cease doing/to do cease to do長時間，甚至永遠停做某事。 cease doing短時停止做某事，以后還會接著做。 That department has ceased to exist forever. 那個部門已不復(fù)存在。 The gir

31、ls ceased chatting for a moment when their teacher passed by. 姑娘們在老師走過時，停止了聊天。 6 try doing/to do try to do努力，企圖做某事。 try doing試驗，試著做某事。 You must try to be more careful. 你可要多加小心。 I tried gardening but didn't succeed. 我試著種果木花卉，但未成功。 7 go on doing/to do go on to do做了一件事后，接著做另一件事。 go on doing繼續(xù)做原來做的事

32、。 After he had finished his maths，he went on to do his physics. 做完數(shù)學(xué)后，他接著去做物理。 Go on doing the other exercise after you have finished this one. 作完這個練習(xí)后，接著做其他的練習(xí) 8 be afraid doing/to do be afraid to do不敢，膽怯去做某事，是主觀上的原因不去做，意為"怕"； be afraid of doing擔(dān)心出現(xiàn)doing的狀況、結(jié)果。 doing 是客觀上造成的，意為"生怕，恐怕

33、"。 She was afraid to step further in grass because she was afraid of being bitten by a snake. 她生怕被蛇咬著，而不敢在草叢中再走一步。 She was afraid to wake her husband. 她不敢去叫醒她丈夫。 She was afraid of waking her husband. 她生怕吵醒她丈夫。 .9 be interested doing/to do interested to do對做某事感興趣，想了解某事。 interested in doing對某種想法感

34、興趣，doing 通常為想法。 I shall be interested to know what happens. 我很想知道發(fā)生了什么事。 (想了解) I'm interested in working in Switzerland. Do you have any idea about that? 我對在瑞士工作感興趣。你想過這事嗎?(一種想法) 10 mean to doing/to do mean to do打算、想 mean doing意味著 I mean to go, but my father would not allow me to. 我想去，但是我父親不肯讓我去

35、。 To raise wage means increasing purchasing power. 贈加工資意味著增加購買力。 11 begin(start) doing/to do begin / start to do sth begin / start doing sth. 1)談及一項長期活動或開始一種習(xí)慣時，使用doing. How old were you when you first started playing the piano? 你幾歲時開始彈鋼琴？ 2)begin, start用進行時時，后面動詞用不定式to do I was beginning to get ang

36、ry。 我開始生起氣來。 3)在attempt, intend, begin, start 后接know, understand, realize這類動詞時，常用不定式to do。 I begin to understand the truth。 我開始明白真相。 4)物作主語時 It began to melt. 12 感官動詞 + doing/to do 感官動詞 see, watch, observe, notice, look at, hear, listen to, smell, taste, feel + do表示動作的完整性，真實性；+doing 表示動作的連續(xù)性，進行性 I s

37、aw him work in the garden yesterday. 昨天我看見他在花園里干活了。(強調(diào)"我看見了"這個事實) I saw him working in the garden yesterday.（強調(diào)"我見他正干活"這個動作） 昨天我見他正在花園里干活。 典型例題 1）They knew her very well. They had seen her _ up from childhood. A. growB. grewC. was growingD. to grow 答案：A。因題意為，他們看著她長大，因此強調(diào)的是成長的過程，而

38、非正在長的動作，因此用see sb do sth 的句型。 2）The missing boy was last seen _ near the river. A. playingB. to be playingC. playD. to play 答案A. 本題強調(diào)其動作，正在河邊玩，應(yīng)此用see sb. doing sth句型。 省to的動詞不定式 1） 情態(tài)動詞( 除ought 外，ought to)： 2） 使役動詞 let, have, make： 3） 感官動詞 see, watch, look at, notice , observe, hear, listen to, smell

39、, feel, find 等后作賓補，省略to。 注意：在被動語態(tài)中則to 不能省掉。 I saw him dance. =He was seen to dance. The boss made them work the whole night. =They were made to work the whole night. 4） would rather，had better： 5） Why / why not： 6） help 可帶to，也可不帶to, help sb (to) do sth： 7） but和except：but前是動詞do時，后面出現(xiàn)的動詞用不帶to的動詞不定式。 8

40、） 由and, or和than連接的兩個不定式，第二個to 可以省去： 9） 通常在discover, imagine, suppose, think, understand等詞后，可以省去to be： He is supposed (to be) nice.他應(yīng)該是個好人。 10）but作介詞，后接不定式結(jié)構(gòu)時，前面謂語動詞部分若含有do的形式時，but后的不定式要省去to，否則要帶to。 He wants to do nothing but go out. He wants to believe anything but to take the medicine. 11）當(dāng)兩個或多個不定時

41、短語由連詞and，but或or連接時，后一個或幾個不定式符號to常省略。但若表示對比、對照關(guān)系時，則不能省略。 He wants to move to France and marry the girl. The purpose of new technologies is to make life easier,not to make it more difficult. 12）不定式做表語時，一般要帶to，但若主語部分中含有do的各種形式時，符號to可省去。 We've missed the last bus.All we could do now is walk home. 舉例

42、： He wants to move to France and marry the girl. He wants to do nothing but go out. 比較：He wants to do nothing but go out. He wants to believe anything but to take the medicine. 典型例題 1)I usually go there by train. Why not _ by boat for a change? A. to try goingB.trying to goC.to try and goD.try going

43、 答案：D. why not 后面接不帶to 的不定式，因此選D。 2） Paul doesn't have to be made _. He always works hard. A. learnB. to learnC. learnedD. learning 答案：B. make后接不帶to 的動詞不定式，當(dāng)其用于被動時，to 不可省略。 注意區(qū)別用作介詞的toto 有兩種用法： 一為不定式+動詞原形； 一為介詞+名詞/動名詞, to 在下面的用法中是第二種，即to+ 名詞/動名詞： admit to承認，confess to承認，be accustomed to 習(xí)慣于，be used to 習(xí)慣于， stick to 堅持， turn to開始，著手于， devote oneself to 獻身于，be devoted to 致力于， look forward to 盼望，pay attention to 注意 不定式一般式的用法一、表示將來 即表示發(fā)生在謂語動作之后的動作。如： We decided to leave early. 我們決定早點動