高中英語動(dòng)詞不定式的用法二

1、動(dòng)詞不定式的用法（二）動(dòng)詞不定式的句法功能：動(dòng)詞不定式在句中可充當(dāng)主語、表語、賓語、賓補(bǔ)、定語和狀語等。一、作主語：不定式作主語時(shí)，通常表示一個(gè)具體的，特定的行為。其謂語動(dòng)詞用第三人稱單數(shù)形式。動(dòng)詞不定式作主語可位于句首。例如：To live means to create.To do that sort of thing is stupid.To learn a skill is very important for everyone in society.但是當(dāng)作主語的不定式是較長(zhǎng)的短語是，我們通常使用it作形式主語，而將動(dòng)詞不定式置于句末。例如：It is necessary for y

2、oung students to learn a foreign language.It was his job to repair bicycles(自行車)常用it作形式主語，而用動(dòng)詞不定式作實(shí)際主語的常用句型有：1. It isadj (for sb.sth.) to do sth.表示“做某事對(duì)某人來說怎么樣”。通常表明的是事情對(duì)人產(chǎn)生的影響或意義。比如“難易程度、重要性、可能性大小等”。用于此句型的形容詞有：easy, hard, difficult, possible, important, impossible, necessary, good, bad, exciting, i

3、nteresting, surprising等。例如：It is interesting to play this game.It is necessary for you to change your job. How rude it was of the boy to jump the queue!It is friendly of the family to try to make me feel at home in their house. How silly it was of you to give up such a good chance！2. Its +

4、adj.+of+sb.+不定式”表示“某人(做某事)怎么樣”。 通常表示根據(jù)事實(shí)判斷人的品行，特征。如：“聰明，愚笨，明智，錯(cuò)誤等”。注意：這一句型中常用描述不定式的邏輯主語的性格、品質(zhì)的形容詞，如good(好的)，kind(友善的)，nice(友好的)，polite(有禮貌的)，clever(聰明的)，foolish(愚蠢的)，lazy(懶惰的)，careful(細(xì)心的)，careless(粗心的)，wise(明智的)，right(正確的)，wrong(錯(cuò)誤的)等。 3.Itbe名詞不定式用于此句型的名詞有：pity, shame, pleasure, ones duty, ones

5、0;job, fun, joy, good manners, bad manners等。例如：It's our duty to take good care of the old. What a pity it is for you to have missed such a wonderful film. It is good manners for the young to give their seats to the old. It's a shame for you to do such kind of thing.4. It takes sb.s

6、ome timeto do sth. 該句型意為“做某事花費(fèi)某人多長(zhǎng)時(shí)間”。例如：It took us half an hour to ride to the town by bike. 2、 作表語主語和表語同為不定式時(shí)，通常主語表示條件，表語表示結(jié)果。如：To see is to believe.動(dòng)詞不定式作表語常用于以下結(jié)構(gòu)：My wish/ job/ aim/ goal is+不定式以及The next step/ /important thing/problem/measure is +不定式等。例如：My wish is to be a teacher.My goal is to

7、pass the college entrance examination(高考，大學(xué)入學(xué)考試).The problem is how to get there.The important thing in life is to have a great aim.(目標(biāo))Your job is to type the papers in the office.The next measure is to stop the river from being polluted.另外：A)當(dāng)主語是一個(gè)由what引導(dǎo)的從句時(shí)，用作表語的不定式通常是說明what的具體內(nèi)容的。如：What I want

8、is to go to the park tomorrow.B)不定式作表語常常用來表示預(yù)定要發(fā)生的動(dòng)作，或表示未來的可能性或假設(shè)。如：His greatest wish is to see an end to the war.All you have to do is (to) finish the job as quickly as possibly.All I can do is just smile at him and say nothing.注意：當(dāng)主語中含有實(shí)義動(dòng)詞do的各種形式時(shí)，作表語的不定式通常省略“to”.3、 作賓語許多動(dòng)詞都可和不定式搭配，即這些動(dòng)詞的用法決定了其后接

9、帶to的不定式作賓語。有些動(dòng)詞只能接“疑問詞+不定式”作賓語。而句中的主語常常就是作賓語的不定式的邏輯主語。常見的只能使用動(dòng)詞不定式作賓語的動(dòng)詞有：agree, choose, decide, hope, fail, wish, refuse, expect, manage, plan, intend, pretend, promise, offer, afford, demand, arrange等。 而常常接“疑問詞+不定式”作賓語的動(dòng)詞有：decide,discover,forget,inquire（詢問），know,learn,remember,see,settle,think,won

10、der.例如：They decided to build a highway between these two cities.She offered to help me when I was in trouble.He promised not to tell anyone about it.I don't decide/know what to do/where to go.I can't remember what to do.I forgot how to operate the machine.注意：當(dāng)作賓語的不定式是較長(zhǎng)的短語，常常用it作形式賓語，而把真正的不定

11、式放到句末去。常常這樣用的動(dòng)詞有believe, think, consider, find,feel, make等動(dòng)詞?？蓸?gòu)成句型“動(dòng)詞+ it +adj. / n+to do sth.”句型，其中使用it作形式賓語，而將真正的賓語動(dòng)詞不定式置于句末。例如：I think it necessary for us to have a good rest after the long work.She felt it her duty to help the old woman.I find it difficult to understand him. 四、作介詞賓語動(dòng)詞不定式通常不能用作介詞

12、的賓語，但以下兩點(diǎn)除外。1） 介詞之后可以用“疑問詞+不定式”作賓語。如：He gave me some advice on how to write a good composition(作文).He talked with me about how to spend the frigid(極寒冷的) winter.2) 以下介詞之后常常用不帶to的不定式作賓語，特別是當(dāng)句中的謂語動(dòng)詞為實(shí)義動(dòng)詞do的各種形式時(shí)，尤其如此。而謂語動(dòng)詞為其他動(dòng)詞時(shí)，也可用帶to的不定式。這類介詞主要有：About就要。Save除。之外But除了。之外Save and expect除。之外Except除。之外Th

13、an除。之外如：I have done nothing except eat and sleep this week.I couldn't do anything but wait here.The enemy(敵人)had no other choice but/than to surrender(投降).敵人除了投降之外，別無選擇。It had no effort except to make him angry.除了讓他生氣外，這起不了任何作用。在下列短語后，but之后只能跟不帶to的不定式。Do nothing but 只能Cannot but禁不住。Do anything b

14、ut決不Cannot choose but只得。Cannot help but不得不如：His father could do nothing but wait for the doctor to arrive.We would do anything but confess(承認(rèn))our guilty.我們決不承認(rèn)有罪。She couldn't help but laugh at his clothes.她情不自禁地大笑他的著裝。I cannot but admire(欽佩) his courage.I could not choose but love her.我不禁愛上了她。作賓

15、補(bǔ)不定式作賓補(bǔ)時(shí)，其邏輯主語常常就是它前面的賓語。1)可后接動(dòng)詞不定式作賓補(bǔ)的動(dòng)詞有：advise, allow, ask, beg, cause, challenge(挑戰(zhàn)), convince(使信服), dare, drive(驅(qū)使), encourage, expect, forbid, force(強(qiáng)迫), hire, instruct(指導(dǎo)), invite, need, order, permit(允許), persuade, require, teach, tell, urge, hear, order, see, want, wish, worn(警告)等。例如： The d

16、octor advised her not to eat too much sugar.I wish you to go to the meeting with me.I persuaded him to give up smoking.She asked me to stay here.2)注意：有一類表示見解，看法的動(dòng)詞，如：believe, consider, count, declare, deny, feel, find, guess, imagine, judge, know, prove, realize, suppose, think等動(dòng)詞后常常接to be型不定式作賓補(bǔ)。to

17、 be可以省略。例如：He declared himself （to be） a college student. 他自稱是名大學(xué)生。The police proved him （to be ）a thief. 警察局證實(shí)他是小偷。We consider him (to be ) diligent(勤奮的). 特別注意 hope, demand, suggest等動(dòng)詞不能后接動(dòng)詞不定式作賓補(bǔ)。例如：【誤】I hope my son to be back soon.【正】I hope my son will be back soon.【誤】She suggests us to have a di

18、scussion about it.【正】She advises us to have a discussion about it.【正】She suggests that we (should) have a discussion about it.3)在主動(dòng)結(jié)構(gòu)中，下列動(dòng)詞后作賓補(bǔ)的動(dòng)詞不定式應(yīng)省略to：“五看”(see, watch, notice, observe, look at)“三使”(make, let, have)“兩聽”(hear, listen to)“一感覺”(feel)。例如：His boss made/have/let him work all day long.I

19、 heard him sing in her bedroom.I saw him play basketball on the playground.但是，改為被動(dòng)結(jié)構(gòu)后，應(yīng)該還原省略的to。例如：He was seen to break the window.4) 表示好惡的動(dòng)詞+賓語+帶to的不定式如：I like people to tell the truth.She preferred me to do my job by myself.I hate him to speak loudly in the classroom.這類動(dòng)詞主要有：Dislike不喜歡Like喜歡Prefer

20、更喜歡Hate討厭，不喜歡Love喜愛Want想要5） Know和see的用法當(dāng)它們用于主動(dòng)語態(tài)，特別是用于一般過去時(shí)或過去完成時(shí)，其后的賓語補(bǔ)足語常?？梢允÷浴Ｈ纾篒 have never known him (to) tell a lie(謊言)I have never known/seen it (to) snow in July before.I never knew her complain.我從沒聽她發(fā)過怨言。注意：當(dāng)know和see用于被動(dòng)語態(tài)時(shí)，必須還原不定式符號(hào)to。如：I have never seen that man (to) smile.That man has ne

21、ver been seen to smile.五、作定語 動(dòng)詞不定式作定語，應(yīng)位于所修飾詞語之后，即：作后置定語。被修飾的名詞和用作定語的不定式之間可能是邏輯主語，也可以是邏輯賓語的關(guān)系。例如：Have you got anything to eat? (to eat修飾anything，位于其后)Do you have anything to say/declare(宣布)？What I want is to get something to do.1)下列名詞后常接動(dòng)詞不定式作定語：ability, attempt, chance, courage, decision, effort, e

22、vidence, failure, means, measure, reason, refusal, promise, right,way, wish等。例如：But she gave up the chance to go abroad.You have no right to speak.He has the ability to work out the math question.I have the courage to invite her for dinner.She has a great wish to to travel around the world.2) 當(dāng)謂語動(dòng)詞是

23、be, find, get, give, have, need, want等，它們后面的名詞（賓語或者表語）常常用不定式修飾。 如：They gave us a week to think the problem over. Do you have anything more to say? We found a house to live in. I need/want a piece of paper to write on. 3) 注意：如果需要另外引出作定語的不定式的邏輯主語，可以用介詞for+名/代詞 如：Mike is the person for me to turn to(求助

24、于) in difficult time. 遇到困難，麥克是我可以向之求助的人。 This is the only point for us to pay attention to. 這就是我們需要給以關(guān)注的唯一一點(diǎn)。4) 如果作定語的不定式為“動(dòng)詞+介詞”，介詞不可省略。如：We must find a hotel to live in because it is getting dark.(live in a hotel)Please give me a piece of paper to write on.(write on a piece of paper)There are a lo

25、t of goods(商品)to choose from.(choose from the goods)5)由only, first, last, next, only, second以及序數(shù)詞或形容詞最高級(jí)修飾的名詞后，也常接不定式作定語。例如：Who was the last one to leave the classroom last night?She was the first girl to come to the party.He is the only person to know the thing.This is the best film to be played th

26、at year.這是那年放映的最好的電影。The cheapest products(商品，產(chǎn)品)to be bought is in that store. 6)在there be句型中，作定語的不定式可以用主動(dòng)或者被動(dòng)。如：There is nothing to worry about/to be worried about. There is a lot of work to do/be done. Is there anything to eat? 7) 有些不定式作定語，具有“將來實(shí)現(xiàn)”的意義，即不定式動(dòng)作將在將來發(fā)生。如：The meeting to take place is v

27、ery important for the company.即將召開的會(huì)議對(duì)這個(gè)公司極其重要。 The person for you to talk with is the manager.將和你談話的人是經(jīng)理。 六、作狀語動(dòng)詞不定式作狀語，可表示目的、原因、結(jié)果或條件。1) 作目的狀語：不定式的動(dòng)作稍晚于謂語動(dòng)詞的動(dòng)作。如：I must leave now to get there on time.我必須馬上動(dòng)身，以便按時(shí)到達(dá)那兒。I am saying this to encourage you.I store the food in the fridge to keep it fresh

28、.We went there to see our grandparents.A)注意：不定式表示目的時(shí)，常常在不定式前面加上in order或so as，構(gòu)成in order to或so as to，以突出或強(qiáng)調(diào)目的。如：Many people go to work on foot in order to /so as to lose weight.I got up so early in order to catch the early bus.He worked so hard so as to get high salary(薪水).B)in order to 和so as to 的否

29、定式是在to前面加not，構(gòu)成in order not to 和so as not to.He studied in his bedroom so as not be disturbed.C)in order to既可以放在句首表目的，亦可以放在句中，而so as to 只能放在句中。In order to catch the early bus, I get up early every day.=I get up early every day so as to catch the early bus.2) 不定式作結(jié)果狀語時(shí)，總是出現(xiàn)在被修飾的動(dòng)詞之后，并且常用以下結(jié)構(gòu)： 結(jié)構(gòu)中文含義S

30、o+形容詞/副詞 +as to do如此。以致Such+（形容詞+）名詞+as to do如此。以致Enough+名詞+to do足夠。名詞/形容詞/副詞+ enough+to do足夠。Too+形容詞/副詞+to do太。以致不能。如：What have I said to make you so angry?What have I done to offend you?They said goodbye, never to meet again.用so.as.和such.as.引導(dǎo)的結(jié)果狀語：He is not so stupid as to do that.他還沒用蠢到去做那種事情。He

31、 got up so early as to catch the first bus.他起的如此早，以致他趕上了頭班車。She is such a beautiful girl as to be liked by people.He is such a strong boy as to carry that heavy box.由too.to引導(dǎo)的結(jié)果狀語，意為“太。以致不能?！盨he is too young to attend school.The food is too hot to eat.I am too tired to study any more.注意：A)如果too 前有al

32、l,but,not,only等修飾時(shí)，too的意思是“非常、很”，這種情況下，即使too后面跟了不定式，也不含否定意義，不表示結(jié)果。I am not too sad to see them leave.看到他們離開了，我并不感到很悲傷。I am not too happy to meet you.見到你，我并不很高興。I am only too pleased to help you.我十分樂意幫助你。B)當(dāng)too和以下形容詞連用時(shí)，即使其后跟有不定式，也不表示否定，too意為“非常。”這些形容詞有：Pleased高興的Glad高興的Apt易于。Anxious焦急的Willing愿意的Ready愿意的Eager渴望的Kind好心的Inclined傾向于。如：I am too glad to see you.Food is too apt to go bad in summer.She is to