动词不定式专题讲解

e.g. Do you have anything to send? 你有什么东西要寄吗
动词不定式作状语
不定式作状语可以表示行为的目的、结果、原因、条件等。 1. 表示目的 I’m saving up to buy a computer.
有时为了强调或突出这种目的，也可以用in order (not) to do, 和so as (not) to do结构 (so as to do不可以置于句首)。
不定式:是一种非限定性动词。 1.非限定动词:是指那些在句中不能单独充当
谓语的动词; 2.动词不定式在句中可以作句子除谓语之外
的任何句子成分。 3.动词不定式没有人称和数的变化。
一、不定式的构成
1) 基本形式： to+动词原形 2) 其否定形式是: “not/never to do”/not do. 3) 不定式可以带宾语或状语构成不定式短语，
I wish you to stay with us.
7) Her story made us laugh. (改成被动句） We were made to laugh by her story.
动词不定式作定语
位置： 放在被修饰词的后面 I have a lot of work to do. I want to find something to drink.
have
notice
listen to
二听
一感觉 feel
hear
注意
1> help 后面的“to”可省去
e.g. They often help the grandma (to) carry water.
2> see, hear, watch, feel, notice, look at等表示 感觉和let, make, have等表示使役的动词后 面，不定式作宾语时要省“to” （注：被动 语态不省to）
2）To waste time is to shorten life. （翻译成中文） 浪费时间就是缩短生命。
动词不定式作宾语
动词+ to do sth.
常用动词有：
want / wish / like / would like / hope / plan / try / decide / learn / need / agree / begin / start / forget / remember / manage / seem / fail/ manage/ promise等
warn, tell, allow, help, ask, force等
作宾补
The teacher told me to clean the blackboard.
I expect you to give me some help.
watch
let
五看
see
三使 make
look at observe
必 背 ： 不定式表示结果常见于下列句型
1) so...as to do Would you be so kind as to lend me your
bicycle? 2) such...as to do
We are not such fools as to believe him. 3) enough to do
动词不定式作宾补
1、动词 + 宾语（sb./sth.) + to do sth.
1）The teacher asked her to answer the question. 2）The doctor told me to have a good rest. 常用动词有：ask, tell, allow, want 等
He didn't run fast enough to catch the train. 4) only to do
He lifted a rock only to drop it on his own feet. 5) too...to do
His eyesight is too poor to read such small letters.
答案：B. make后接不带to 的动词不定式，当其用 于被动时，to 不可省略。
3> 不定式用在介词but, except, besides后时, 如果这些介词前有行为动词do的各种形式,那 么介词后的不定式不带to,相反则带to.
1) She could do nothing but cry. 2) I have no choice but to go. 3)What do you like to do besides sleep.
1. 单个不定式作主语时，谓语动词用单数。 2. 不定式作主语时，往往放在谓语之后，用it 作形式主语。
动词不定式作主语
It +be + adj. +for/of sb. to do sth. for: adj.多 为 描 述 不 定 式 行 为 的 特 征 （ important/ necessary / interesting 等.） of: adj. 多为 描述主语的品质特征 （kind / nice / friendly / wise / foolish 等.）
Practise
• 1.He got up early so that he could catch the first bus to the town.
• He got up early_____ _____ _____ catch the first bus to the town.
练习
1) Let him __f_in_i_s_h_ the work at once. (finish / to finish)
2) Do you like listening to other people__t_a_lk__? (talk / talking/to talk )
3) Jim was seen __t_o_e_n_t_e_r_the room. (enter /to enter )
不定式为不及物动词时后面应有必要的介词。 I’m looking for a hotel ___D____. A. stay B. stay at C. to stay D. to stay at
动词不定式作定语
I have something to say. He has a lot of homework to do . He is looking for a room to live in . There is nothing to worry about.
式 She came here to study English. 状语
I warned the patient not to eat cold water after the operation. 宾补
三、用法/功能
动词不定式作主语
To see is to believe. It’s important to learn English well .
没有人称和数的变化。
二、动词不定式的结构
肯定： to + V.原 或者 (to)+ V.原 否定：not/never + (to) + V.原
1) He likes to read novels. 2) I saw him come. 3) We decided not to buy that house. 4) It is interesting to fly a kite. 5) Please let him not go there.
e.g. I made him do his work.
He was made to do his work (by me).
典型例题
1) I usually go there by train.
Why not ___ by boat for a change?
A. to try going
B. trying to go
﹚ every day .
to do
3. The old man has a house
_________ ﹙住﹚.
to live in
4. She is a nice person__________ ﹙
共事﹚ .
to work with
4. something, anything, nothing, everything 等复合不定代词常用不定式做后置定语。
To do that sort of thing is foolish。主语
I want to see you this evening. 宾语
动
词 All you have to do is to finish it quickly. 表语
不 定
We found a house to live in. 定语
C. to try and go D. try going
答案：D. why not 后面接不带to 的不定式，因此 选D。
2) made ___. He always works hard.
A. learn B. to learn C. learned D. learning
动词不定式作表语
主语 + be + to do sth
主语多为 duty / wish / hope / idea / plan / ambition/ dream / work / job 等 名词
我的梦想是成为一名歌手。 他的工作是每天清扫教室。 1) My dream is to be a singer. 2) His work is to clean the classroom every day.