三、非谓语动词

　　非谓语动词是指动词不定式、动名词和分词，是动词的非限定形式。在句子中它们起着一些特殊的作用。

　　(一)动名词

　　动名词也是动词的一种非限定形式，由动词原形加词尾ing构成。以下主要介绍其做定语及状语的情况。

　　1.作宾语

　　(1)介词+动名词可以作状语用，表示时间、原因、目的、让步、方式等。

　　He was blamed for having done something wrong.

　　They went to Manchester with the object of winning the World Championship.

　　(2)作动词宾语

　　有些动词要求动名词作宾语，这类动词有：admit，advise，avoid，delay，excuse，finish，

　　imagine，mind，postpone，practise，require，resist，risk，suggest，stand等。

　　If you practise diving often，you will learn how to doit.

　　Sorry I have delayed answering your letter.

　　2.作定语

　　Wear shortens the effective working life of machine pans.

　　(二)动词不定式

　　不定式是指带to的动词原形(使用中有时不带to)，在句中起形容词或副词的作用，可

　　以作状语和定语。

　　1.作定语

　　(1).动词不定式与其修饰的词之间往往有动宾关系，如果该不定式是不及物动词，其后

　　应有合适的介词。

　　He's a pleasant fellow to work with.

　　There's nothing to worry about.

　　⑵有些名词后常跟不定式作定语。例如：time，reason，chance，right，ability，willingness，need，anxiety，wish，plan等。

　　Women should have the right to receive education.

　　There is no time to hesitate.

　　⑶the first，the second，the last，the best等之后用不定式做定语。

　　The monitor will be the first to come.

　　He was the last man to blame.

　　2.作状语

　　⑴作目的状语

　　不定式作状语时，其动作发生在谓语动词之后，一般置于句子末尾。但是，如果表强

　　调，亦可置于句首。

　　He went to Shanghai to visit his parents.

　　To save the earth，we must prevent the earth from being polluted.

　　⑵作独立成分

　　有些固定词组带to不定式，表明说话人的立场或态度，在句中作独立成分。这些词有：

　　to be honest, to be begin with，to cut a long story short，to get (back)to the point，not to make much of it，to put it another way，to tell the truth等。

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

　　To be honest，I have never heard of Winston Churchill.

　　⑶作结果状语

　　We came home after our holiday to find our garden neat and tidy.

　　She left home never to return again.

　　⑷作原因状语

　　不定式作原因状语时，一般放在句子末尾。

　　She burst into laughter to see his funny action.

　　The boy was shocked to see the frightening scene.

　　(三)分词

　　分词是动词的三种非限定形式之一，包括现在分词和过去分词两种。分词可以在句中作状语及定语。

　　1.现在分词的用法

　　现在分词可在句中作定语和状语。

　　⑴作定语

　　现在分词作定语时多置于它所修饰的名词前：

　　This is apressing question.这是一个紧迫的问题。

　　He asked an embarrassing question.他提了一个令人难堪的问题。

　　现在分词亦可置于它所修饰的名词之后：

　　There were no soldiers drilling.

　　现在分词短语一般皆置于其修饰的名词之后：

　　A little child learning to walk often falls.

　　The men working here are all from rural areas.

　　⑵现在分词用做状语

　　现在分词及其短语从表意的角度看，也可用做状语，表示时间、原因、结果、条件、让步、方式或伴随情况等。其动作可能发生在谓语动词之前或之后，也可能与谓语动词的动作同时发生。

　　①表示时间

　　Climbing to the top of the tower，we saw amgnificent view.

　　He went out shutting the door behind him.

　　强调与谓语动词的动作同时发生时，现在分词之前可用连词when或while：

　　When leaving the airport，they waved to us again and again.

　　While flying over the Channel，the pilot saw what he thought to be a meteorite.

　　②表示原因

　　Being sick，I stayed at home.

　　She caught cold sitting on the grass.

　　③表示条件

　　Adopting this method，we will raise the average yield by 40 percent.

　　Turning to the right，you will find a path leading to his cottage.