1. 用法分类 主语：
To buy a flat in a high-rise is their dream. To help others is our duty.
It is important to see one’s own weaknesses. It is necessary for us to meet again. 宾语：
Here was a mystery he wanted to solve.
She learnt to live on her own when she was in college. When she is nervous, she does nothing but eat. At the moment, we can do nothing but wait. 表语：
What you can do now is （to） have a good rest. Their plan is to build a school in the neighborhood. 定语：
The only way to get him is to watch the papers. His dream to become a doctor came true. 状语：
They would hide until the time was ripe to swoop down on the criminals. They took a taxi to get here. 宾语补语：
They told me to wait outside. 2. 形式（时态与语态） 进行形式：
I happened to be sitting in the classroom when the earthquake occurred. He pretended to be reading a book when I came into the room. 完成形式：
He seemed to have forgotten everything. Nothing seems to have changed.
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She appeared to have been a great athlete. He pretended to have seen the movie before. 被动形式：
What’s to be done next? Children all want to be loved.
The patient is pleased to have been taken good care of in the hospital. 否定形式：
It’s very hard not to make any mistakes. We finally decided not to go by air.
The teacher asked the children not to make any noise in class. 能够直接接不定式的动词：
afford; agree; arrange; attempt; expect; fail; happen; hesitate; hope; intend; manage; offer; plan? 1.不定式表示结果 too?..to 太?..而不能 形容词或副词+enough +不定式
It is not cold enough to wear a heavy jacket. So?.as to 如此?以至?
Would you be so kind as to turn down the television? Only to do 表示无法预料的后果
I went to see him only to find him out. 2.不定式放句首，表示目的。
A: Why was the official meeting called? B: new officers.
A. Select B. Selecting C. To select D. for selecting 正确答案：C 表示目的
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不定式
1．构成
由to + 动词原形构成，有时也可以省去to. 否定式由 not + 不定式构成。 2 用法
（1） 作主语、宾语、表语、定语、状语和宾语补足语。
e.g. To make a plan for our future is very important.(主语) How to get enough capital is still a problem (主语) I like to go out for a walk in such warm sunshine.(宾语) She can’t decide what to do. (宾语)
Perhaps this would be a good chance to go to Hainan.（定语）
Could you get me something to drink? (定语) Her wish is to marry an honest young man. (表语) His plan is to spend a few days in the mountain. (表语)
In 1918,he went to Japan to study medical science. (状语，表目的)
A few years later, she came home to find that her hometown had greatly changed.
(状语，表结果)
Would you like us to go with you? (宾补) Did you notice him leave the house? (宾补) He was asked to make a speech at the meeting (主补) They were made to work day and night. （主补） （2） 作主语时，为了使句子保持平衡，往往有it 作形式主语，而把不定
式放在谓语动词后面。
e.g. It is important for us to learn English well.
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（3） 作 使役动词 let, make, have 以及感官动词 see, hear, watch,
observe, notice, feel, smell ,listen to, look at的宾语补足语时 动词不定式不带to
e.g Mrs Brown made me stay in New York for two more weeks. She won’t let her son watch TV until he finishes his homework..
（4） 所有的疑问词后面都可以接带to的不定式构成不定式短语，（why not
后面接不带to 的不定式）。 如 where to go , what to do, which to choose from, how to get there, why not join us
（5） 下列常考动词只能接不定式作宾语
agree, attempt, claim, decide, demand, ask, hesitate, beg, fail, care,, promise, desire, hope, intend, learn, offer, plan, refuse, prepare, pretend, require, appear, arrange, expect, manage, tend, afford, wish, seem, swear, threaten, wait 等 e.g, Tom pretended to have been studying
I have managed to run as fast as I could in race.
（6） 下列情况接不带to 的不定式
A. had better, would rather, would sooner, may/might as well, rather than, sooner than, can’t help but(情不自禁)等 e.g You’d better not go out alone at such a dark night. B. 当but/except 前面有do 的某种形式时， 后接不带to的不定式，如
do nothing but/except ?.do anything:; everything but/ except
e.g. I would sooner die than marry you.
He doesn’t want to do anything expect help me.
( 7) 不定式作定语时，它和它所修饰的名词之间要构成动宾关系，如果
是不及物动词则要加上适当的介词来构成动宾关系
e.g Could you find someone for me to play table tennis with?
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