高中英语不定式用法
动词不定式的特征和种类
动词不定式是由不定式符号to+动词原形构成，在某些情况下to也可省略。
A． 不定式的一般式 不定式的一般式表示的动作通常与主要谓语 的动作同时或几乎同时发生，或是在它之后发生。 He appears to be very happy. 他看起来好像很高兴。（同时发生）
To catch the train, we'd better hurry to the station by taxi. 为了赶上火车，我们最好赶紧乘出租车去车站。（to catch the train发生在hurry to the station之后）
B．不定式的进行式 不定式的进行式表示正在进行的动作。
It happened to be raining when I got there. 我到达那里的时候，天碰巧在下雨。
C． 不定式的完成式成都青白江区风险等级 不定式的完成式表示的动作在谓语表示的动作之前发生。
I'm sorry to have lost your key. 我很抱歉把你的钥匙弄丢了。
D． 不定式的完成进行式 不定式的完成进行式表示的动作在谓语之前发生并且一直进行着。
He was said to have been living in London for twenty years. 据说他在伦敦一直住了20年。
比较： 不定式的时态意义。
He is said to be studying abroad. 据说他正在国外读书。（不定式的进行式表示动作正在进行）
He is said to have studied abroad. 据说他在国外学习过。（不定式的完成式表示动作已经结束）
E． 不定式的被动形式 当不定式逻辑上的主语是这个不定式表示的动作的承受者时，不定
式一般要用被动形式。不定式的被动形式根据其与谓语动作发生的先后关系，有一般式和完成时两种。
1．一般式 to be done
These are the books to be given out to the students. 这些是要发给学生的书。
2．完成式 to have been done
The novel is said to have been translated into many languages. 据说这部小说已被译成多种语言。
F. 不定式的否定形式------- 不定式的否定形式由not或never加不定式构成。
We decided not to go out because of the bad weather. 由于天气不好，我们决定不出去。
注意：谓语动词的否定和不定式的否定不同的意义北戴河旅游民宿哪里好
I did not promise to wake him up. 我没有答应叫醒他。
I promised not to wake him up. 我答应了不叫醒他。
To see one time is better than to hear a hundred times.
To persevere means victory!
注①：在很多情况下，特别是在口语中，常采用先行it代替主语，而把不定式后置：
It’s a great pleasure to be here.
It is not an easy thing to master a language.
注②：这种后置不定式的结构也适用于某些谓语动词不是系动词的句子，如：
It took us five hours to get there.
It made us very angry to hear him talk like that.
注③：不定式结构的逻辑主语通常可在特定的上下文或情景中看出，也可以由“ for + 名词词组” 来表示，如： It is not hard for one to do a bit of good.
It was difficult for me to do the work.
注④：某些形容词在上述结构中作表语时，常在不定式之前加上 “of + 名词词组” 来说明不定式所指的是谁的情况，如：
It’s kind of you to think so much of us.
It’s very nice of you to be so considerate.
It’s unwise of them to turn down the proposal.
It was careless of her to make such a mistake.
二、不定式结构作表语
1．主语和表语都是不定式（其含义往往一是条件，一是结果），如：
To be kind to the enemy is to be cruel to the people.
To do that would be to cut the foot to fit the shoe.
2．主语是以aim, duty, hope, idea, intention, mistake, plan, proposal, job, suggestion 等为中心词的名词词组，或以 what 引导的名词性从句表示，后面的不定式说明其内容，如：
My idea is to climb the mountain from the north.
Your mistake was not to write that letter.
My suggestion is to start work at once.
What I would suggest is to start work at once.
注：在某些句型中，当主语部分有动作动词do 时，作表语的不定式可以省略符号 “to”，如：昆明滇池国家旅游度假区
All we have to do is push the button.
The only thing I can do now is go on by myself.
All I could do was send him a telegram.
三、不定式结构作动词宾语
1．“动词 + 带 to 的不定式结构”。这类动词常见的有：afford, agree, arrange, ask, choose, decide, demand, desire, expect, hope, learn, manage, offer, pretend, promise, refuse, want, wish, like, hate, prefer, continue, try, start, forget, mean, intend, begin, 等，例如：
I’ve arranged to meet him at ten o’clock.
I didn’t expect to find you here.
2．“动词 + 疑问词 + 带 to 的不定式结构”。（这种不定式结构接近一个名词从句）。这类动词常见的有：tell, advise, show, teach, find out, decide, discuss, learn, forget, inqu
ire, know, explain, remember, see, understand, wonder 等。
疑问词（也称连接代/副词）有：what, where, who(m), when, how, whether, which（why 除外），如：
I don’t know what to do / where to go / who(m) to ask / when to stop / how to get there.
I haven’t decided whether to sell it or not.
We must find out what to do next / where to put it.
注① ：如果作宾语的不定式结构有自己的补语，则应使用先行 it，把不定式后置，例如：
I find it difficult to understand him.
We thought it wrong not to help her.
They found it impossible to get everything ready in time.
衡水职业技术学院注② ：不定式结构一般不可作介词宾语, 只有在个别场合, 即在含有否定意义的带有介词 except 或 but (=except) 的结构中才能这样用，例如：
莲花山风景区图片He seldom comes except to look at my pictures.
The child did nothing except weep.
She can do anything but sing.
He will do anything for you except lend you money.
They could do nothing but wait for the doctors to arrive.
注意不定式符号的省略问题！
网上怎么订酒店住宿四、不定式结构作定语
1．不定式作定语通常只能放在被修饰的名词之后，如：
It’s time to go to bed.
He is not a man to bow before difficulties.
Have you anything to declare?
She usually has a lot of meetings to attend in the evening.
I want to get something to read during the vocation.
2．能带不定式结构作宾语的动词，转化成名词时往往也能带不定式结构作定语，如：
