1．不定式的基本形式与结构

2．不定式的用法

1)不定式结构作主语

1.Te get contact with his family in Taiwan made him extremely happy since they separated more than 40 years ago．

2.To finish that task in such a short time is really a challenge．

1.It made him extremely happy to get contact with his family in Taiwan since they separated more than 40 years ago． 2.John admitted that it is always difficult for him to be on time．

2)不定式作宾语 不定式作宾语有两种：一种是及物动词后直接跟带to的不定式， 另一种是“及物动词+疑问词+带to的不定式。

1.He managed to solve the complicated problem. 2.The stranger offered to show me the way. 3.Mr. Smith undertook to build a new plant in South Africa.

1.He does not know when to start. 2.You can decide whether to continue or to stop. 3.I will show you how to deal with it.

3)不定式做表语 一种情况为主语是不定式(表示条件)；表语也是不定式(表示结果)：

1.To see is to believe.2.To work means to earn a living．

4)不定式作定语 不定式结构作名词词组修饰语主要有三种类型：

5)不定式作状语 不定式结构在句中作状语通常都能转换为限制性状语从句。例如作原因状语： 1.They are quite surprised to see the great changes taking place in the area． 2.They are quite surprised because they see the great changes taking place in the area． 3.He was lucky to arrive before dark． 4.He was lucky because he arrived before dark．

1) 在can／could， /may／might，will／would，shall／should，must， need，dare等情态动词之后，动词不定式不带to。

2)在表示感觉意义的动词，如see初中英语语法总结，feel，watch，notice，smell，hear，observe等后，或是表示“致使”意义的动词，如have，let，make等后，动词不定式不带to。例如： 1.I often heard him say that he would study hard． 2.I must have him see his own mistakes． 但是，当这类结构转换为被动语态时，后面的不带to不定式一般转换为带to不定式。 例如： 1.He was often heard to say that he would study hard． 2.After he had finished speaking，he was made to answer innumerable questions．

3)在动词help之后可用不带to的不定式，也可用带to的不定式。例如： 1.Help the old lady (to) carry the heavy box.

4) 在had better，would rather，may／might as well，rather than，can not but等搭配之后初中英语语法总结，动词不定式也不带to。例如： 1.Unless you feel to ill to go out，I would rather not stay at home tonight． 2.She could not but criticize his foolish behaviour.

5) 在make do，make believe，let drop，1et fall，1et fly，let slip，let drive，let go off，hear say，hear tell，leave go of等固定搭配中，用不带to的动词不定式。例如： 1.They let go of the rope．他们松开了绳子。 2.John let fly a torrent of abuse at me．约翰朝我痛骂了一顿。 3.I've heard tell of him．我听说过他。

6)在介词but初中英语语法总结初中英语语法总结，except之后，如果其前有动词do的某种形式，其后不定式一般不带to，反之则必须带to，表示“不得不初中英语语法总结，只能”。例如：

1.He will do anything except work on the farm．

2.There was nothing left for the enemy to do but surrender．

3.The spy was both hungry and cold；there was nothing left for him but to give in．

4.I had no choice but to wait till it stopped raining．

7)紧跟在why或why not之后的动词不定式总是不带to。但是，紧跟在who，what，which，whether等连接词后的不定式带to。例如： Why stand up if you can sit down? Why not ask your teacher when you don't understand the meaning? You needn't decide yet whether to study arts or science． 4．不定式的完成式和进行式 1)构成 完成式：to+ have done 进行式：to+ be doing