在句中充當(dāng)除謂語(yǔ)以外的句子成分的動(dòng)詞形式叫做非謂語(yǔ)動(dòng)詞。非謂語(yǔ)動(dòng)詞分為三種形式:不定式、動(dòng)名詞和分詞(分詞包括現(xiàn)在分詞和過(guò)去分詞)
一、不定式
(一)不定式的作用
1、作主語(yǔ) 不定式作主語(yǔ)時(shí),謂語(yǔ)用單數(shù)。往往用it 作形式主語(yǔ),把不定式放在謂語(yǔ)后面。如:
It took us two hours to finish the job.
It is impossible for us to get there on time.
It is very kind of you to help us.
注意:(1)其他系動(dòng)詞如look, appear等也可用于此句型。
(2)當(dāng)不定式作主語(yǔ)的句子中又有一個(gè)不定式作表語(yǔ)時(shí),不能用It is …to…的句型。試比較:
It is to negate my own idea to believe him.(錯(cuò))
To believe him is to negate my own idea .(對(duì))
(3)It is+ adj. of / for sb. to do sth. 結(jié)構(gòu)中,當(dāng)不定式的邏輯主語(yǔ)和前面的形容詞可以構(gòu)成系表結(jié)構(gòu)時(shí),用of, 否則用 for.
2、作賓語(yǔ)
動(dòng)詞+不定式。如:
He managed to escape from the fire.
I find it hard to get along with him.(it 作形式賓語(yǔ))
注:下列動(dòng)詞通常用不定式作賓語(yǔ):want, try, hope, wish, need, forget, know, promise, refuse, help, decide, begin, start, learn, agree, choose, get等
動(dòng)詞+疑問(wèn)詞+to , “特殊疑問(wèn)句+不定式”相當(dāng)于名詞,作賓語(yǔ)。如:
I don’t know what to do next/ how to do it next.
I can’t decide when to go there.
注意:不定式短語(yǔ)作賓語(yǔ)時(shí),如果還帶有賓語(yǔ)補(bǔ)足語(yǔ),往往把不定式短語(yǔ)放在賓語(yǔ)補(bǔ)足語(yǔ)之后,用it 作形式賓語(yǔ)。如:
I find it necessary to learn a foreign language.
3、作賓語(yǔ)補(bǔ)足語(yǔ)
動(dòng)詞+賓語(yǔ)+不定式(to do )。如:
He warned me to be careful.
I want you to speak to Tom.
What makes you think so?(不帶to的不定式)
注:可以用動(dòng)詞不定式做賓補(bǔ)的動(dòng)詞有:ask, tell, order ,want ,get, would like, like, advise, invite, allow, help, wish,warn, expect, prefer, encourage
表見(jiàn)解、看法的動(dòng)詞結(jié)構(gòu)可為:動(dòng)詞+賓語(yǔ)+ to be 的不定式結(jié)構(gòu)。如:
We consider Tom to be one of the best students in our class.
The book is believed to be useful.(被動(dòng)語(yǔ)態(tài))
(3) There +不定式。如:
We didn’t expect there to be so many people there.我們沒(méi)料到會(huì)有那么多人在那里。
注意:(1)有些動(dòng)詞需用 as 短語(yǔ)作補(bǔ)語(yǔ),像regard, think, believe, take, consider。如:
We regard Tom as our best teacher. 我們認(rèn)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。
(2)在動(dòng)詞feel (一感),hear, listen to(二聽(tīng)),have, let, make(三讓),notice, see, watch, observe, look at(五看)(即:吾看三室兩廳一感覺(jué))等后面的補(bǔ)足語(yǔ)中,不定式不帶to,但變?yōu)楸粍?dòng)語(yǔ)態(tài)后,必須帶to。如:
They saw the boy fall off the tree. The boy was seen to fall off the tree.
(3)help后面作賓語(yǔ)補(bǔ)足語(yǔ)的不定式可以帶to,也可以不帶to.
I often help him (to)clean the room.
I helped him (to) find his things.
4、作定語(yǔ)
不定式作定語(yǔ),修飾名詞或代詞,不定式和它所修飾的名詞之間有邏輯上的主謂關(guān)系、動(dòng)狀關(guān)系、同位關(guān)系或動(dòng)賓關(guān)系。不定式通常要放在這些被修飾的詞后。如:
I have a lot of work to do.(動(dòng)賓關(guān)系)
He is looking for a room to live in.(動(dòng)狀關(guān)系)
He is the first person to think of the idea.(主謂關(guān)系)
He has got a chance to go abroad.(同位關(guān)系)
注意:1.不定式的邏輯主語(yǔ)是句子的主語(yǔ)時(shí),不定式用主動(dòng)形式表被動(dòng)。如:
Do you have anything else to say?
2.如果作定語(yǔ)的不定式是一個(gè)短語(yǔ),則要保留不定時(shí)短語(yǔ)中的副詞或介詞。如:
I need a pen to write with . (I will wirte with the pen ) (我需要一直鋼筆寫(xiě)字)
I have a little baby to look after .(I must look after the little baby ) (我有一個(gè)嬰兒要照看)
5、作狀語(yǔ),表示目的、結(jié)果、原因等,有時(shí)還有一些固定搭配的不定式短語(yǔ),如in order to , so as to, so…as to, such …as to, ….enough to, too…to等。
做目的狀語(yǔ),to, only to (僅僅為了), in order to, so as to, so(such)….as to…(如此···以便···)如:
He ran so fast as to catch the first bus. 他飛快地跑以便趕上第一班車(chē)。
He came to the school to see his son.
作結(jié)果狀語(yǔ),表事先沒(méi)有預(yù)料到的,要放在句子后面。如:
He hurried to the post office only to find it was closed.
He searched the room only to find nothing.
做原因狀語(yǔ)。如:
We were very excited to hear the news.
I’m glad to see you.
做條件狀語(yǔ)。如:
To turn to the left , you could find a post office.
6、作表語(yǔ)
不定式可放在be動(dòng)詞后面,構(gòu)成表語(yǔ)。如:
The question is how to put it into practice.
My question is when to leave.
His dream is to be a doctor.
Her work is to look after the babies.
注意:1.不定式在句中作表語(yǔ)時(shí),對(duì)應(yīng)的謂語(yǔ)動(dòng)詞用單數(shù)。
2.當(dāng)助于是不定式時(shí),表語(yǔ)不能用Ving形式,可用不定式。
如:To see is to believe. (眼見(jiàn)為實(shí))
7、獨(dú)立結(jié)構(gòu)。如:
To tell you the truth, I don’t agree with you.
To make matters worse, it began to rain.
(二)不定式的時(shí)態(tài)和語(yǔ)態(tài)
1、不定式的時(shí)態(tài)
現(xiàn)在時(shí):有時(shí)與謂語(yǔ)動(dòng)詞表示的動(dòng)作同時(shí)發(fā)生,有時(shí)發(fā)生在謂語(yǔ)動(dòng)詞的動(dòng)作之后。如:
He seems to know this. I hope to see you again.
完成時(shí):表示的動(dòng)作發(fā)生在謂語(yǔ)動(dòng)詞表示的動(dòng)作之前。如:
I’m sorry to have given you so much trouble.
He seems to have caught a cold.
進(jìn)行時(shí):表示動(dòng)作正在進(jìn)行,與謂語(yǔ)動(dòng)詞表示的動(dòng)作同時(shí)發(fā)生。如:
He seems to be eating something.
完成進(jìn)行時(shí):表示動(dòng)作從過(guò)去某個(gè)時(shí)間開(kāi)始,一直延續(xù)到現(xiàn)在,并有可能持續(xù)下去。如:
She is known to have been working on the problem for many years.
2、不定式的語(yǔ)態(tài)
當(dāng)不定式的邏輯主語(yǔ)是其動(dòng)作的承受者時(shí),就用被動(dòng)式。如:
He was seen to enter the hall. He asked to be sent to work in Tibet.
(三)省to 的動(dòng)詞不定式
1、情態(tài)動(dòng)詞(除ought 外,ought to)
2、Would rather, had better.
3、感官動(dòng)詞 see, watch, look at, notice, observe, hear, listen to, smell, feel 等后作賓補(bǔ),省略 to.
注意:在被動(dòng)語(yǔ)態(tài)中 to 不能省略掉。如:
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、使役動(dòng)詞 let, have, make.
5、由 and, or 和 than 連接的兩個(gè)不定式,第二個(gè) to 可以省去。如:He wants to move to France and marry the girl.
Help 可帶 to ,也可不帶to, help sb. (to) do sth.
Why…/Why not…
6、But 和 except 前是動(dòng)詞 do 時(shí),后面出現(xiàn)的動(dòng)詞用不帶 to 的動(dòng)詞不定式。試比較: He wants to do nothing but go out.
He wants to believe anything but to take the medicine.
7、通常在discover, imagine, suppose, think, understand 等詞后,可以省去to be .如:
He is supposed (to be) nice. 他應(yīng)該是個(gè)好人。
——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
Paul doesn’t have to be made ______ . He always works hard.
A learn B to learn C learned D learning
(四)、 動(dòng)詞不定式的否定式。如:Tell him not to shut the window. She pretended not to see me when I passed by.
Mrs. Smith warned her daughter ______ after drinking.
A never to drive B to never drive C never driving D never drive
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 do
The patient was warned ______ food before the operation.
A to eat no B eating not C not to eat D not eating