1、 基础知识清单 不定式有俩种表现方式，一种是带to的不定式，一种是省略to的不定式。 不定式不能做谓语，但它具有动词的一些特征，如可以带有自己的宾语、状语、及逻辑主语等。它没有人称和数的变化，但有时态和语态的变化。

2、 考点分类剖析考点一：动词不定式的时态

1) 一般式（to do）：表示的动作或状态与谓语动词表示的动作同时发生或在其后后发生，如：

E.g. I want to have a holiday as soon as possible. He seems to know the secret.

2) 完成式（to have done）：表示的动作在谓语动词表示的动作之前就发生了

E.g. I am sorry to have given you so much trouble.

3) 进行式（to be doing）：表示或者强调其动作与谓语动词表示的动作同时发生

E.g. This city seems to be getting more and more crowded.

4) 完成进行式（to have been doing ):表示的动作在谓语动词表示的动作之前已经发生，并仍在进行，而且还可能继续下去

E.g. Tom seems to have been watching TV for a long time.

考点二：动词不定式的语态

1) 当不定式逻辑上的主语是这个不定式所表示的动作的承受者时，不定式要用被动形式（to be done）

E.g. He asked to be sent to work in the countryside.

) 不定式修饰的名词或代词和不定式逻辑上构成主谓关系时，不定式用主动形式，如：

E.g. Have you got a key to unlock the door?

3) 不定式前面的名词或代词与不定式构成逻辑上的动宾关系，但又与该句的主语构成逻辑上的主谓关系的时候，不定式常用主动形式，如：

E.g. I have got a letter to write. He needs a room to live in.

4) 不定式作表语形容词的状语，和句子中的主语构成逻辑上的动宾关系时，不定式多用主动形式，如 E.g. The book is difficult for us to understand.

5) 如果强调句中动作的承受者时，亦可用不定式的被动式，上面的句子可以写成:

E.g. The book is difficult for us to be understood.

考点三：动词不定式的句法功能 由于动词不定式具有名词、形容词和副词的特征，所以动词不定式在句中可以作主语、表语、宾语、定语、状语和补语。

1) 作主语 E.g. To ask him for help is necessary. To ignore this might have serious consequences. 注意:动词不定式做主语时，常用it来作形式主语，把真正的不定式或不定式短语放在后面，如:

E.g. To talk with him is a great pleasure.=It is a great pleasure to talk with him.E.g. Her wish is to become a pop star.She does not seem to like the idea.

2) 作宾语1 常用动词不定式作宾语的有：want、hope、wish、offer、fail、plan、learn、pretend、refuse、manage、help、agree、promise、prefer、afford、ask、decide、except、intend etc.

E.g. ou must learn to look after yourself.

2 若不定式后面有宾语补足语，则用it来作形式宾语，把真正的 宾语放在补足语的后面，如：E.g. I find to work with him interesting.

3) 作定语

1 不定式作定语的时候，须放在被修饰的名词或代词的后面；不定式常和它修饰的词有动宾关系；如果这个不定式是不及物的，它后面必须要有介词.

E.g. There is nothing to think about. We must find a room to live in.

2 不定式用来修饰已经被序数词、最高级或no、all、any等限定的中心词，且与中心词为主动关系

E.g. He was the best man to do the job. She was the first woman to win the gold medal. = I find it interesting to work with him.

4) 作宾补

1 动词不定式在feel、hear、see、watch、notice、observe等感官动词以及have、let、make等使役性动词后面作宾语补足语时，不定式符号要省略；但若是这些句子变成被动语态结构时，就必须带to，如： E.g. I saw him cross the street. He was seen to cross the street.

2 不定式可以和名词或代词构成复合宾语（即“宾语+宾补”结构）； 常跟不定式作宾补的动词有：ask、tell、invite、get、advise、allow、want、permit、warn、encourage、prefer、expect、order、wish等；而且有些动词常跟“to be +形容词”构成的复合结构，如think，consider, imagine, prove, understand, find, know, suppose等，如：

E.g. The doctor advised him to have a good rest. We proved the facts to be correct.

5) 作状语1 作目的状语E.g. I got up early in order to catch up the first bus.

2 在某些形容词后面作状语E.g. I am glad to see you again./ Nice to meet you.

3 作结果状语 …only to 表示出乎意料的结果

E.g. I hurried to the postoffice, only to find it closed.

Too…to… 太……而不能……

E.g. The girl is too young to dress himself

当too前有only修饰时，即“only too…to…”，表肯定意义

E.g. I am only too pleased to help you.

当too…to…前有表示否定意义的词的时候，表肯定意义

E.g. We are never too old to learn.

考点四：“疑问词+不定式”结构

1) 疑问代词who，what，which 和疑问副词when，where，how等后面加上不定式，构成具有名词作用的短语，可以用作主语，表语和宾语等。

2) 在tell，know，advise，teach，find out，decide，discuss等动词后常用“疑问词+不定式”这一结构 E.g. When to start has not been decided.(作主语) The question is how to put the plan into practice.(作宾语) No one could tell me where to find the book.(作宾语)

考点五：动词不定式省略to的特殊形式

1) 动词不定式在but、other than后面的时候，如果but和other than 前面行为动词do的某种形式的话，那么其后的不定式要省略to（否则要带to）

E.g. He can do nothing but / other than wait. He had no choice but to wait.

2) 在cannot choose but 、cannot help but (只好)、cannot but(只好)、had better、would rather等后面的不定式也要省略to

E.g. I cannot but agree to his terms. I would rather stay than do anything else.