[動詞不定式的簡介]
動詞不定式是一種非限定性動詞,非限定動詞是指那些在句中不能單獨充當(dāng)謂語的動詞,分為不定式,動名詞,現(xiàn)在分詞和過去分詞,由to＋動詞原形構(gòu)成,但在有些情況下to可以省略.在句中不能單獨作謂語.它具有動詞的性質(zhì),本身可以帶賓語和狀語.動詞不定式在句中可以作除了謂語之外的任何成分,還可用在復(fù)合結(jié)構(gòu)中,而且有完成式、進行式、完成進行式和否定形式.動詞不定式的被動形式除了一般形式外還有其完成式和進行式.
[編輯本段][動詞不定式的時態(tài)、語態(tài)]
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：
主動形式 被動形式
一般式 （not） to make （not） to be made
完成式 （not） to have made （not） to have been made
進行式 （not） to be making
完成進行式 （not） to have been making
(1)語態(tài)
如果動詞不定式的邏輯主語是這個不定式所表示的動作的承受者,不定式一般要用被動語態(tài)形式.如：
It's a great honour to be invited to Mary's birthday party.（不定式作主語）
It was impossible for lost time to be made up.（不定式作主語）
I wish to be sent to work in the country.（不定式作賓語）
Can you tell me which is the car to be repaired?（不定式作定語）
He went to the hospital to be examined.（不定式作狀語）
在There be結(jié)構(gòu)中,修飾主語的不定式可用被動,也可用主動.如：There are still many things to t ake care of (to be taken care of).但有時兩種形式表達的意思不同,如：These is nothing to do now.( We have nothing to do now.) There is nothing to be done now.(We can do nothing now.)
(2)時態(tài)
1) 現(xiàn)在時：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.
I hope to see you again. = I hope that I'll see you again. 我希望再見到你.
2) 完成時：表示的動作發(fā)生在謂語動詞表示的動作之前.
I'm sorry to have given you so much trouble.
He seems to have caught a cold.
3) 進行時： 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.
4) 完成進行時：
She is known to have been wreaking on the problem for many years.
[編輯本段][疑問詞＋不定式結(jié)構(gòu)]
疑問詞who,what,which,when,where,whether,how后可接不定式構(gòu)成不定式短語,在句中作主語、賓語、表 語等.如：
①When to leave for London has not been decided yet. （不定式在句子中做主語）
②Mr. Smith didn't know whether to leave or stay there. （不定式在句子中做賓語）
③I asked Professor Xu how to learn English well. （不定式在句子中做間接賓語）
④The question was where to get the medicine needed. （不定式在句子中表語）
以上例句中疑問詞＋不定式部分,均可轉(zhuǎn)換為相應(yīng)的從句形式.如：①When we shall leave…③…h(huán)ow I
could learn…
經(jīng)常在這種結(jié)構(gòu)中使用的動詞有：consider,decide,discover,explain,find out,forget,hear,know,lea rn,observe,understand,wonder等.
[編輯本段][動詞不定式的語法功能]
一、作主語
動詞不定式作主語時,句子的謂語動詞常用單數(shù),其位置有以下兩種：
(1)把不定式置于句首.如：
To get there by bike will take us half an hour.
(2)用it作形式主語,把真正的主語不定式置于句后,常用于下列句式中.如：
①It＋be＋名詞＋to do
It's our duty to take good care of the old.
②It takes sb+some time+to do
How long did it take you to finish the work?
③It＋be＋形容詞＋for sb＋to do
It is difficult for us to finish writing the compositionin a quarter of an hour.
④It＋be＋形容詞＋of sb＋to do
It is stupid of you to write down everything the teachersays.
⑤It seems(appears)＋形容詞＋to do
It seemed impossible to save money.
在句型③中,常用表示客觀情況的形容詞,如：difficult,easy,hard,important,impossible,necessary 等；在句型④中,常用careless,clever,good,foolish,honest,kind,lazy,nice,right,silly,stupid,wise等 表示贊揚或批評的詞.在不定式前的sb,可看作其邏輯主語.這一句式有時相當(dāng)于Sb is＋形容詞＋to do句式 ,如：It'skind of you to help me with my English.=You are kind to helpme with my English.
(3)舉例
1） It's easy (for me) to do that.我做這事太容易了
easy, difficult, hard, important, possible, impossible, comfortable, necessary, better;
the first, the next, the last, the best, too much, too little, not enough
It's so nice to hear your voice.
聽到你的聲音真高興.
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.
2) It's very kind of him to help us. 他幫助我們,他真好.
Kind, nice, stupid, rude, clever, foolish, thoughtful, thoughtless, brave, considerate(考慮周到的), silly, selfish(自私的)
例句:
It was silly of us to believe him. 我們真愚蠢,竟然相信了他.
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.
二、作賓語
1) 動詞+ 不定式
afford. aim. 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. undertake.
舉例：
The driver failed to see the other car in time.
司機沒能及時看見另一輛車.
I happen to know the answer to your question.
我碰巧知道你那道問題的答案.
2）動詞+不定式 ；動詞+賓語+不定式
ask, beg, choose, expect , hate, help intend like, love, need prefer, prepare, promise, want, wish…
I like to keep everything tidy. 我喜歡每件東西都保持整潔.
I like you to keep everything tidy. 我喜歡你使每件東西都保持整潔.
I want to speak to Tom. 我想和湯姆談話.
I want you to speak to Tom. 我想讓你和湯姆談話.
3） 動詞+疑問詞+ to
decide, know, consider forget, learn, remember, show, understand, see, wonder, hear, find out, explain, tell
Please show us how to do that. 請演示給我們?nèi)绾稳プ?
There are so many kinds of tape-recorders on sale that I can't make up my mind which to buy.有這么多的錄音機,我都拿不定主意買哪一種.
注意:疑問詞帶不定式在句中作成分時,謂語動詞用單數(shù).
The question is how to put it into practice.
問題是怎樣把它付諸實施.
4)以下動詞后,只能跟不定式作賓語.
如：agree,ask,aim,arrange,choose,decide,demand,expect,fail ,help,hope,lean,long,manage,offer,plan,prepare,
pretend,promise,refuse,wish 等,這些詞大部分可接that引導(dǎo)的從句.如：
I decided to ask for my money back.
I decided that I would ask for my money back.
When our visit to the farm was over,we expected to startback on foot.
When our visit to the farm was over, we expected that wewould start back on foot.
5)當(dāng)復(fù)合賓語中的賓語是不定式時,先用形式賓語it代替不定式,把不定式置于補語之后,即：主語＋動 詞＋it＋補語＋to do句式.如：
We think it quite important for us to learn a foreignlanguage well.
He feels it his duty to help the poor.
三、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 induce inform instruct invite judge know like order permit persuade remind 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.
I found him lying on the ground.
I found it important to learn.
I found that to learn English is important.
典型例題:
The next morning she found the man ___ in bed,dead.
A. lying B. lie C. lay D. 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.現(xiàn)在分詞表達主動,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
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 Babbage is generally considered ___ the first computer.
A. to invent B. inventing C. to have invented D. 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 reported, hope, wish, desire, want, plan, expect, mean…
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
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, take, 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.
四、作表語
不定式作表語表示具體動作或?qū)韯幼鳎粍用~作表語表示抽象的一般行為.
①To be kind to the enemy is to be cruel to the people.
②My chief purpose is to point out the difficulties ofthe matter.
③What 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（例①）.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②）時,或以what引導(dǎo)的名詞性分句（例③）,不定 式說明主語的內(nèi)容.
④Our work is serving the people.
⑤What he likes is taking a walk after supper.
⑥The story told by Mr.Wang is interesting.
④⑤句動名詞作表語,與主語部分可以轉(zhuǎn)換,如Serving thepeople is our work,而⑥句中是現(xiàn)在分詞作 表語,說明主語的性質(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.
五、作狀語
1）目的狀語
To… only to (僅僅為了), in order to, so as to, so(such)… as to… (如此……以便……)
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 room 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. sit B. sit on C. be seat D. 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.
六、作定語
⒈不定式作定語
不定式在句中作定語,置于被修飾的名詞或代詞之后.如：
①The next train to arrive is from Washington.
②Have you anything to be taken to your sister?
③Do you have anything to say on the question?
④Would you please give me some paper to write on?
⑤My wish to visit France has come true at last.
不定式短語作定語和被修飾詞之間表示以下關(guān)系：
(1)表示將來的動作（例①）.
(2)與被修飾詞之間有動賓關(guān)系,如是不及物動詞,則需加介詞（例④）.
(3)與被修飾詞之間有動賓關(guān)系,同時與句中其它詞之間又有邏輯上的主謂關(guān)系時,盡管有被動含義,卻仍 用主動語態(tài)（例③）；如只有動賓關(guān)系,而無邏輯上的主謂關(guān)系,則需用被動語態(tài)（例②）.
(4)不定式作定語時,一般可轉(zhuǎn)換為定語從句,例①to arrive=that will arrive.
[編輯本段][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, 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） 表示個人意愿或傾向的would rather,had better,might(just) as well：rather than置于句首時.
Rather than ride on a crowded bus,he always prefers to ride a bike.
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） 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.
典型例題
1) ---- I usually go there by train.
---- Why not ___ by boat for a change?
A. to try going B. trying to go C. to try and go D. try going
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. learn B. to learn C. learned D. 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.
[編輯本段][動詞不定式的否定式]
Tell him not to shut the window…
She pretended not to see me when I passed by. 我走過的時候,她假裝沒看見.
典型例題
1）Tell him ___ the window.
A. to shut not B. not to shut C. to not shut
D. not shut
答案：B. tell sb to do sth 的否定形式為tell sb not to do sth.
2) She pretended ___ me when I passed by.
A. not to see B. not seeing C. to not see
D. having not seen
答案：A. pretend 后應(yīng)接不定式.其否定形式為pretend not to do sth..
3）Mrs. Smith warned her daughter ___ after drinking.
A. never to drive B. to never driver
C. never driving D. never drive
答案：A.warn sb to do sth. 的否定形式為warn sb not to do sth. 此處用的是否定詞never.
4) The boy wanted to ride his bicycle in the street,but his mother told him ____.
A. not to B. not to do C. not do it
D. do not to
答案：A.not to 為not to do it 的省略形式.可以只用to這個詞,而不必重復(fù)整個不定式詞組.及物動詞do后應(yīng)有名詞、代詞等,否則不對,因此B,D不對.
5) The patient was warned ___ oily food after the operation.
A. to eat no B. eating not C. not to eat
D. not eating
答案：C.warn一詞要求后用不定式,此處為不定式的被動,否定形式為be warned not to do.
[編輯本段][不定式的特殊句型]
1、不定式的特殊句型so as to
1） 表示目的；它的否定式是so as not to do.
Tom kept quiet 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?
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 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too…to…
1）too…to 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 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.
3) 當(dāng)too 前面有only, all, but時,意思是：非?！?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 eager to get home. 他非常想回家.[動詞不定式的'to'與介詞的'to'區(qū)別] to 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
介詞but,except,besides+to do(do)
在這種句型中,如介詞前有動詞do,后面應(yīng)接不帶to的不定式；如無do,則接to不定式,即帶do不帶to, 帶to不帶do.如：
The enemy soldiers had no choice but to give in.
On Sunday afternoon I had nothing to do but watch TV.
[編輯本段][動詞不定式與動名詞區(qū)別與聯(lián)系]
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)在下列情況下,一般要用不定式：
①hate,like,love前有would(should)時,如：I'd like to have a cup of coffee.
②當(dāng)謂語動詞begin,continue,start等是進行式時,如：Thestudents are starting to work on the di fficult maths problem.
③begin,continue,start與know,understand等狀態(tài)動詞連用時,如：I soon began to understand what was happening.
⒋advise,allow,encourage,forbid,permit等動詞后接動名詞作賓語,或帶不定式作賓語補足語.如：
Our teachers don't permit our/us swimming in the lake.
Our teachers don't permit us to swim in the lake.
4） 部分動詞后接不定式或動名詞時,意義差別較大,應(yīng)根據(jù)句子語境選擇使用.
①forget,remember,regret后接不定式,表示現(xiàn)在或未來的動作,接動名詞表示動作已經(jīng)發(fā)生.如：
Don't forget fo post the letter for me.
Have you forgotten meeting her in Beijing Airport?
Remember to close the windows before you leave.
I remember writing him a letter a year ago.
We regret to tell you that all of you are not invited toattend the meeting.
They regretted ordering these books from abroad.
動名詞與不定式語義不同的有11 組：
1 stop to do stop doing
2 forget to do forget doing
3 remember to do remember doing
4 regret to do regret doing
5 cease to do cease doing
6 try to do try doing
7 go on to do go on doing
8 afraid to do afraid doing
9 interested to do interested doing
10 mean to do mean doing
11 begin/ start to do begin/ 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.
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