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（3）动词不定式做状语

  动词不定式做状语时，一般表示目的，有时表示出乎意料的结果。在形容词的后面时有时表示原因，形容词一般是glad, sorry, proud, angry, ashamed excited, disappointed, interested等等表示感情的词。例如：

I’m sorry to hear that. 表原因

He is amazed for Mary to receive that letter from a stranger.表原因

He is happy for his daughter to marry a rich man.表目的

In order for his son to study abroad, he has been very thrifty for ten years. 表目的

He escaped the sword only to perish by famine. 他躲过了战争却死于饥荒。表结果

He tried to kill himself only to be saved. 表结果

做状语的不定式，可做评注性状语，对整个句子加以评述。例如下面的短语就常做这类状语：

To be honest, to speak frankly, to speak generally, to cut a long story short 等等

（4）不定式做表语

不定式做表语，一般都是回答主语（表示物或事情）是什么，有的书上解释成做主语补足语；动名词也有类此的用法，它们之间的区别在于：不定式一般比较具体，带有更多的修饰成分；动名词较抽象，一般带有的修饰成分少。分词做表语多是说明主语所处的状态, 特点, 性质,等等。例如：

My purpose is to help him.

His plan was to set up a big company.

His hope is for every student to work eight hours a day.

What impressed him most was to see the great changes that had happened there. 给他印象最深的是看到那里所发生的巨大变化。不定式做表语

The mountain is covered with snow all around the year. 山上终年覆盖着雪。过去分词做表语

比较：The glass is broken. 那个玻璃杯坏了。The glass was broken by him.那个玻璃杯是他打坏的。

To see is to believe. Seeing is believing. 眼见为实。不定式或动名词做表语。

My advice is for you to apologize to her. 我的建议是你向他道歉。不定式做表语。

The story he told us is very interesting. 他给我们讲的故事很有趣。

但是，当主语是人或有时是物时，不定式出现在be，remain，等系动词的后面表示要做的事情较多。例如：

The letter is for you to answer.

He is to blame. He is something to blame.

Something remains to do.

在seem，appear， prove等系动词的后面表示状态。例如：

He seems to know it.

He appears to be jobless.

The method proved to be effective.

Be to do 可表示将来计划好安排好的事情，可表示上级对下级的吩咐，要求，命令，也可以表示命中注定要发生的事情。例如：

You are to die at eighty-two. （上天安排。）

One is to struggle for one’s living. （自然安排）

You are to be back by ten o’clock. （吩咐）

Nobody is to say such a thing. （禁令）

If you are to study in Europe, you must learn about a foreign language.

Apples are to (can) be bought everywhere.

（5）动词不定式做补足语

  不定式做补足语常表示经常发生，反复发生的动作。也可以表示瞬间完成的动作；现在分词做补足语表示正在发生的事情，或表示一个过程；过去分词表示被动，多数表示完成，但有些没有完成意思。例如：

  He saw him come in. 我看见他进来了。比较：I saw him coming in. 我看见他正走进来。

  I often see him play on the playground. I just saw him playing the playground.

  They had the light burning all the night. 他们让灯整夜的亮着。

  She will have her hair cut this afternoon. 她今天下午去理发。

  动词want，order的后面有跟动词不定式的被动式表示被动，表示要做事情。例如：

 They don’t want the land to be built. 他们不想让土地用于建筑。

The emperor ordered all the walls to be joined up. 皇帝命令把所有的城墙都连接起来。

We believe him to be honest.

He declared the rumor to be false.

  在下列动词的后面不定式做宾补时，需要省略to：feel, hear, listen to, let, have, make, look at, see, watch, notice, observe, help等，但是变成被动语态时，省略的to必须在加上。例如：

  I will have him do it for me. He watched the painter paint the door.

  I felt the house shake. Let him come at seven.

  I was made to get up early yesterday. The house was felt to shake.

 （6）不定式做定语

  不定式做定语时，放在不修饰词的后面，常表示要做的事情，带有很强的目的性，如果句中有其动作的发出者常用主动式，强调要做也可以用被动式，如果没有其动作的发出者，则常用被动式。例如：

  He has a lot of things to do.

  The manager told the secretary he had a report to be typed. （从句中）

  An attempt to climb the mountain will be made.

  The order for the army to start was given.

  He needs love to strength his broken heart.

  There is no need to set up at once.

不定式同被修饰词有多种关系，主要如下：1主谓关系，2 同位关系，3 动宾关系 4 形容词与状语的关系，5 动词与宾补关系，等等。例如：

   His fear to see his former wife is natural. 同位关系

   His invitation to attend the wedding was true. 动词与宾补关系

   He has a brother to teach him English. 主谓关系

   He has a house to live in. 动宾关系

   His eagerness to help his mother is doubtful. 形容词与状语关系