非谓语动词：不定式
1.不定式做主语
To不定式可在句中做主语，但在多数情况下常用it作形式主语，将不定式后置。 To tell lies is wrong. It is wrong to tell lies.
To make a speech here is an honour.
It is an honour to make a speech here.
除动词be以外，动词take,require,make也可以用于上述结构： It takes 3 hours to walk there. It requires efforts to master a language.
It made us delighted to find a good book.
在疑问句和感叹句中只能用it作先行词的结构
What a pleasure it is to work with them!
How relaxing it is to bathe in the sun on the sand!在沙滩上沐日光浴多么令人放松！
在it作形式主语的结构中，通常用for+名词或代词作不定式的逻辑主语，表示不定式所表示的动作的特征。
It is possible for him to master the art of speaking.对于他掌握演说艺术史可能的。 It is not right for them to stop the test halfway.他们中途停止试验是不对的。
在It+be+形容词+of+名词或代词+to不定式结构中，该结构表示不定式逻辑主语的特征。用于这个结构的形容词一般是形容人的形容词，如：foolish, clever, stupid,nice,kind,rude,careless等。 It is kind of you to say so. You are kind to say so.
It was careless of him to break the coffee cups. He was careless to break the coffee cups. It was brave of her to save the pupils. She was brave to save the pupils.
2不定式做主语补语
这类结构中的主语一般为名词：idea,hope,purpose, plan, aim, intention, mistake等，不定式用来说明主语的内容
My purpose is to teach them a lesson.我的目的是给他们一个教训。 His mistake was not to take my advice.他的错误是不听我的意见。
3.不定式作动词宾语（搭配问题）
A.动词+to do sth./not to do sth.(否定形式)
这类常用动词有long, want , refuse, pretend, promise, agree, aim, choose, decide, demand, expect, hope, learn, manage, try, afford等 I long to become a football star. He agreed to keep it secret. We’ve decided not to go away. We managed to get to the airport in time. B.动词+疑问词+to do sth.
这类动词有know, decide, wonder, learn ,remember, see ,understand, think ,find out等
I don’t know what to say to calm her.我不知道说什么安慰她。 They are learning how to repair cars. I don’t understand what he’s saying. C.动词+宾语+疑问词+to do sth.
这类动词有show teach advise tell inform
The famer showed us how to milk the cow.农民教我们如何挤牛奶。 Mr Crook taught them how to type.
4.不定式作宾语补足语（搭配） A.动词+宾语+to do sth.
这类动词有wish ask beg expect force invite permit remind want warn allow encourage advise等 The docter advised me to have a blood test.医生劝我验血。 I got them to join us in the discussion.我让他们参加我们的讨论。 He wished her not to leave.
B.动词+宾语+不带to不定式
See hear feel watch observe let notice make have等感觉和使役动词。 I saw the lady lock the door. We didn’t let anyone come in.
I often hear her sing in the next room. C.其他
I have something to say.
I’d like a few books to read during the journey. That’s a nice place to live.（名词place, time, way后接to do ） I’m afraid there is no time to play now.
Mary is always the last to arrive at the office.(序数词后通常接不定式)
We often hear the baby in Room 302. (cry) It is very interesting snowmen in winter. (make) Tom’s ambition is a professional football player. (be) It is very cold today. You’d better your coat when you go out.(put on)
It’s impolite at others or shout at others.( stare)
Our manager asked me something about our company at the meeting.(say)
We all wish fewer mistakes in the test.(make) Father often let me his computer.(use)
It is impossible for me this difficult problem in such a short time. (work out)
Let’s ask him us a favor.(do)
Captain King didn’t ask his crew (discuss) the ways (escape) from the monster.
Why not to have a walk with me?(go out)
I am glad to tell you that you are the first one here.(get) From the window I saw the girl get into the car and away.(drive)
It is easy wise after the event.(be)
He made me him the whole story.(tell) The boy was seen the money.(take)
Why don’t you get your wife it to you?(explain) He is known angry easily.(get)
Mike was looking for someone him.(help) I advised him (ask) the bus conductor where (get)off.
Translation
你不回信太没礼貌了。
请告诉我如何去电影院
爬这样高的山似乎是不可能的
记住这些规则很容易
我还没决定是留还是走
我们最好把答案先核对（check）一下
他告诉我如何学习英语
父母警告（warn）我们不可以在河里游泳。
我希望很快收到你的信
学习数学很简单
他犯了这么多错误，真不小心
