(1)动词不定式： 由 to + 动词原形构成。 可以做主语，宾语，宾补，定语，表语和状语
主语
1. To get there by bike will take us an hour
宾语
2. The river failed to see the car in time
宾补
3. We believe him to be guilty
定语
4. The next train to arrive is from seoul
表语和状语
5. My suggestion is to put off the meeting
6. I come here only to say goodbye to you
（2）动词原形 + ing 可作动名词用，具有动词的特征和变化形式，但在句子中的用法及功能类同名词： 在句子中可以作主语，宾语，表语，定语。它也可以被副词修饰或者支配宾语
1. Reading is an art
2. They went on walking and never stopped talking
3. Your task is quickly cleaning the windows
4. This is a reading room
（3）假主语 / 真主语
to 不定式或动名词可以在主语的位置上， 但一般用 it 代替它作形式主语，这种情况 it 叫形式主语
1. It's a great honor to be invited
2. It is no use crying over spilt milk
在宾语的位置上，用 it 代替它作形式宾语，这种情况 it 叫形式宾语
1. We think it important to learn English
2. I found it pleasant walking in the park
（4）对动名词或不定式进行否定时，在不定式或动名词前加 not 否定就可以了
1. He pretended not to see her
2. He regrets not joining them
（5）to不定式作目的状语
1. in order to + v 表示目的
so as to +v 表示目的
由in order to 引导的目的状语，置于句首，句尾均可。由so as to 引导的目的状语，只能置于句尾。
I've written it down in order to remember it.
0He shouted and waved so as to be noticed
2. 否定形式
I've written it down in order not to forget it
He said nothing so as not to be noticed.
（5）包含不定式和动名词的一些固定结构
1 too ~ to ~ : 太...以至于不能...
The room is too small to live
2 enough + n + to + v / adj +_ enough + to: 足够...可以...
There is enough food to eat.
The box is big enough to contain six apple
3 On - ing: ~ 一 ... 就 ...
On seeing the snake
the girl was very frightened
4. There is no hope of ~ing: 没希望...
There is no hope of seeing him
5. feel like ~ing: 想要
I feel like eating ice cream now
6. have a hard time ~ing: 做~艰难
They have a hard time solving the problem themselves
（6）现在分词/过去分词
1. v + ing 可称之为动名词，也可称之为现在分词
Writing books is his job
He is writing a book
2. 动词的 p.p 形式可称之为动词的过去分词，用在完成时和被动语态当中。
He has written the homework
The homework is written
3. 分词句是包含现在分词和过去分词的分句
The students went out of the classroom, laughing and talking
Accompanied by his friend, he went to the railway station.