动词不定式的省略

1. 只保留动词不定式的符号“to”

   为了避免重复，有时候不定式中的主要动词可以省略。只剩下不定式的符号“to”常保留“to”的动词结构有expect to , love to , like to ,prefer to ,used to , be going to , mean to , ought to , try to , plan to , be happy to , be glad to , be eager to , be willing to , be ready to

   -Would you like to come with us?

   -Yes, I’d love to

   -Do you live here?

   -No, but I used to

   -Would you look after my cat while I am away?

   -I’ll be happy to

   -Will you go together with me

   -Yes, I will be glad to.

   -You can go with us if you want to.

   You don’t know her? But you ought to

   (备注：如果不定式是动词be， 或者have 表示有，be 和have 不能省略，

   -Is your father a reporter?

   -No, but he used to be.

   -I didn’t tell him the news

   -Oh, you ought to have

   Mary is not what she used to be.

2. 不带to的不定式

3. 不带to 的不定式作宾语补足语

4. 在介词except, but，如果有动词do后省略不定式

5. 不带to的不定式作表语

6. 常接不带to 的不定式结构有

   Would rather do something=宁愿做某事情

   Would rather not do sth=宁愿不做某事情

   -Shall we go by train?

   -I would rather go by car.

   - I am tired, I ‘d rather not go out this evening

   Would do sth rather than do sth=宁愿做某事情，也不做某事情

   Do nothing but do sth 只好做某事情

   Why do sth?何必做某事情？

   Why worry about such little things?

   Why not do sth?为什么不做某事情？

   Why not join us in the game?

   Why not stop to have a rest?

   can’t help but 不得不，只

   I can’t help but laugh on hearing his joke.

   我禁不住被他的笑话逗笑了.

   can’t but不得不，只

   I can’t but think so 我不得不这样认为.

   can not choose but 不得不，只

   He cannot choose but stay on.

   have nothing to do but do sth 只能做某事情

The enemy can do nothing but/except surrend.

=The enemy had nothing to choose but /except to surrender.

He did nothing all day long but eat and sleep.

We can do nothing but wait.

We could do nothing but wait.

You can do nothing but wait=you can’t do anything but wait.

had better do sth 最好做某事情

had better not do sth 最好不做某事情

You had better come here on time.

You had better turn the bottle upside down to empty out the oil.

You had better not miss the last bus.

并列不定式通常省略第2个不定式符号

当有两个或者更多不定式并列，而且是用了连词and, or则通常在在第1个不定式加to，后面不定式to常省略.但如果不定式表示对比，则每个都需要加to,以及如果用了逗号，代替了and, or则可加to，也可以不加

He promised to finish my homework and hand it in on time.

I promise to finish the work and hand it in on time.

I hardly know whether to laugh or cry

We ought to read more and have more practice.

I am really puzzled what to think or say

I’d like to stay with you and help you and learn from you.

I came here not to play but to work.

It is better to laugh than to cry.

I promise to finish my homework, (to)hand it in on time.

The boys likes to stay with his brothers,(to) play basketball

The purpose of new technologies is to make life easier but not to make it more difficult.