非谓语动词用法总结
非谓语动词是历年高考英语的重要考点之一，也是较难掌握的难点之一。它贯穿于英语学习和考试过程的始终。但是，只要认真分析、透彻理解、看透本质、准确把握，就一定能在高考中运筹帷幄，游刃有余。
不定式不可作谓语，但它可以有自己的宾语、状语，构成不定式短语，在句中可以作主语、宾语、表语、定语（表用途）、状语或补足语。高考对不定式的考查主要有不定式的时态、语态、作用、否定、省略、连词＋不定式等。
1.作主语
不定式作主语表示具体的动作，通常指一件已知的事或目的。
不定式作主语时，谓语动词用单数。
eg:To say is a thing,to do is another.(说是一回事，做是另外一回事。)
（2）不定式短语较长时，通常放在谓语之后，用it作形式主语。
eg:①It is important to learn English well.(学好英语是重要的。)
②It is necessary for us to do the job well.(我们做好这项工作是必要的。)
③It is a great honor to be invited to give a speech here.(被邀请在这儿发表演讲是一个极大的荣幸。)
2.作宾语
（1）常只用不定式作宾语的动词有：
want,wish,hope,long,expect,desire,intend,decide,ask,promise,aim,offer,agree,plan,learn, choose,refuse,fail,manage,pretend等。
eg:①He refused to help me.(他拒绝帮助我.)
②She has agreed to come tomorrow.(他已同意明天来.)
(2) 不定式较长时，作宾语，也可用it代替，放在后面。
eg;I find it difficult to do the job well.
(3) “特殊疑问词﹢不定式to do结构”具有名词特征，可作宾语。
eg:①She didn’t know whether to go or not.
②They haven’t decided when and where to build the school.
（4）不定式可作介but,except,besides“除……之外”的宾语，介词前有实义动词do的任何一种形式，后边的不定式就无to,否则必带to。
eg:①I want to do nothing but play the computer games。
②I have no choice but to wait。
3.动词不定式作表语
（1）不定式作表语放在be和其他系动词后，说明主语的内容。同样，“特殊疑问词＋不定式”具有名词特征，也可作表语。
eg:①My job is to sweep the floor.
②His goal was to enter the key university of Beijing.
③The first question is how to find a better way to learn English well.
(2)不定式作主语时，表语也必须为不定式，结构必须保持一致。
eg:To see is to believe.
(3)如果主语部分的谓语动词或非谓语动词是实义动词do的某种形式，那么作表语的不定式可以省去to.
eg:①The first thing to do is find her.
②The only thing he could do was tell the truth.
4.不定式作定语
不定式作定语常放在所修饰的名词或代词后。
eg:①I have something important to tell you.(不定式与被修饰名词构成被动关系。)
②His wish to be an artist has never come true.( 不定式与被修饰名词构成同位关系。) He is the right man to do the job. ( 不定式与被修饰名词构成主动关系。)
The little girl was unhappy because she had no friends to play with. ( 不定式与被修饰名词构成主动关系。)（注：若不定式为不及物动词，其后须加上相应的介词。)
5.不定式作状语
不定式作状语主要是表示目的、条件、原因和结果，可位于句首或句末，但句首时通常用逗号隔开。
eg:①We set off early that morning to catch the first bus.（目的）
②To get a good result,she worked very hard.（目的）
③I feel it an honor to be invited to the party.(条件)
④She was very happy to get the first prize.(原因)
⑤He worked hard only to fail.(结果)
(注：1.不定式常用在so as 或in order后,与它们一起作谓语，表示目的，但so as引起的不定式不可置于句首。
eg: In order to avoid mistakes,check your homework.
2.不定式表目的常和only连用，往往表示出乎意料的意想不到的不愿得到的结果。eg:He hurried to the station only to find the train had left.)
3．“形容词＋enough＋不定式”和“too＋形容词或副词（不表情感）＋不定式” 也可作结果状语。
eg:①He is old enough to go to school.
② He is too weak to raise the stone.
但“too＋表情感形容词（pleased,ready,glad,willing,anxious等）＋to do”表示肯定意义，too前面可用only,but等词修饰。
eg:①They were (only) too anxious to leave.(他们只是太急于离开了。)
②She is (only) too pleased to go home.(她非常高兴可以回家了。)
6.不定式作补语
不定式作补语表示动作的完成。宾语与作补语的不定式之间是主动关系。
（1）后接动词不定式作宾补的常见动词有：
want,wish,expect,prefer,like,hate,ask,beg,request,require,beg,get,advise,persuade,invite ,order,remind,permit,allow,send,callon,wouldlike/love,arrange for,depend on等。
eg: ①She wanted me to arrive there early.
②Our headmaster call on us to work hard.
（2）动词不定式可作感官动词（五看二听一感觉即：
see,look at,watch,observe,notice，hear,listen to，feel）和使让动词（let,make,have等）后面的宾补时，不定式符号to要省略，但如果句子变被动结构，必须带to.表示动作的完成。
