一. 动词不定式：在句中可做主语，宾语，表语，定语，状语和补语。

1.1 不定式做主语

To enter this university is my dream cherished for many years.

To understand this situation completely requires more thought than has been given so far.

注意不要头重脚轻：

To live in the present rather than in the past or future is surely not wrong.

It is surely not wrong to live in the present rather than in the past or future.

1.2 不定式做表语

To do two things at a time is to do neither.

An important function of the World Health Organization is to improve the health and living conditions for the sick and the poor of the world.

注意不要头重脚轻:

Perhaps the most urgent problem is to provide enough food.

To provide enough food is perhaps the most urgent problem.

1.3 不定式做宾语（记住固定搭配）

I want to go to the park.

The driver failed to see the other car in time.

Our teacher promised to see the movie with us.

1.4 不定式做定语

The train to arrive was from London.

We have little time to spare.

There will be many difficult problems to deal with.

This is an opportunity to give people more leisure.

1.5 不定式做补语（固定搭配）

This view is thought to be wrong.

Students are required to solve problems in groups.

Television allows one to follow the latest developments in science and politics.

1.6 不定式做状语

目的状语：(也可用in order to/so as to)

To become a teacher in the university, it is necessary to have at least a master’s degree.

结果状语

He woke up to find everyone gone.

only to 表示“结果却”。

The mother loves her children and lets them have their way only to spoil them.

Greatly agitated, I rushed to the apartment and tried the door, only to find it locked.

原因状语

We are proud to be young people of new China.

He shuddered to think of his bitter past.

She can’t help bursting into laughter to see his funny action.

做独立成分(固定表达，注意积累）

To tell you the truth, I have never been to beijing.

To make the situation worse, there is as yet no sign that any slowing of the world’s population is in sight.

To start with……

2. 不定式的时态

2.1不定式的进行时

He pretends to love her.

He pretended to be listening attentively.

They are said to be building houses in that area now.

2.2 不定式的完成时

We are happy to have visited so many historic places here.

I am very sorry to have bothered you with so many questions on such an occasion.

3. 不定式的被动语态

we have decided to invite him to the concert.

It is an honor for me to be invited to the party.

To be promoted is not a matter of salary but even more a matter of self-respect.

3.1 不定式被动语态的完成时

The novel is said to have been translated into seven languages.

Many consumers seem to have been influenced by stock-market swings.