专升本英语语法基本知识（不定式）

今天为大家继续带来了专升本英语语法（不定式）的基本知识，希望大家能够坚持每日打卡，一步一个脚印掌握相应的语法知识点，坚信付出终将有所收获。

1.用法:主语、宾语、表语、宾语补足语、定语、状语等。

eg:To see is to believe. (主、表)

It only took us a year to finish the work. (主，it形式主语)

She wants to play basketball this afternoon. (宾)

She was the first person to think of the idea. (定:主谓关系)

I have nothing to say on the problem. (定:动宾关系)

He asked me to help him. (宾补)

We are all happy to hear of the good news.(状)

◆不定式在let, have, make(让,使)，see, look at, notice, hear, listen to, feel等后面作宾语补足语时to应省略，在被动语态中to应保留。

eg:The coach has the team practice hard every night in the past two years.

I saw a man come into the classroom and talk with the teacher.

We felt the house shake.

Someone was heard to come up the stairs.

◆在help后，不定式可以带to也可以不带to.

eg:Help me (to) get him to bed.

He help her lift the box.

He helped her to mount the bike

She was helped to lift the box.

◆当不定式和其修饰的词有动宾关系时，动词如果是不及物动词，后面就要有必要加介词。

eg:There is nothing to worry about.

I need a pen to write with.

Give me some paper to write on.

2.不定式的逻辑主语

不定式前面可以加for引导的短语作逻辑主语，说明不定式表示的动作是谁做的，或不定式指的是谁的情况。

eg:It is important for us to master English.

It will be a mistake for us not to help them.

I open the door for her to come in.

3.不定式的否定式:not to do

不定式的被动式:to be done

不定式的完成式:to have done(不定式的完成式仅强调其动作发生在谓语动词之前)

推荐阅读

专升本英语语法基本知识（情态动词）