《非谓语动词（3）》
一 不定式做主语
Be careful!To smoke so much is not good for you.
具体的或一次性的动作（to do v-ing?）
Smoking much is not good for you.
表示一般或抽象的经常性的行为和动作
句型:It is+adj.+for/of sb to do sth.
It is very kind of you to help me with my English.
It is very difficult for you to learn English gammar.
二 不定式作宾语
1.爸爸答应给我买一辆单车。
My father promised to buy a bike for me.
2.天啊！我忘了关灯了。
Oh,My God!I forgot to turn off the light.
注意:下列动词或动词短语后只接不定式作宾语:
agree,seem,appear,offer,happen,wish,hope,
pay,expect,long,plan,intend,promise,pretend,
decide,afford,manage,choose,be said to,would like to等
三 不定式作宾语补足语
1.医生建议他每天锻炼身体。
The doctor advised him to take exercise.
2.他的父母期望他上大学。
His parents expected him to go to university.
注意:用不定式作宾语补足语的动词
 以下动词只接不定式作宾语补足语；
advise,allow,ask,beg,cause,expect,force,get,
encourage,hate,invite,order,oblige,wish,want,warn,
remind,promise,permit,persuade,request…
以下动词接动词原形作宾补:
(一)感官及物动词feel,hear,listen to,see,look at,watch,observe,notice,find,smell.
(二)使役动词make,let,have
(感官动词接动词原形作宾语补足语表示动作全过程,而使役动词变被动语态后,作宾补的原形动词前要加“to”)
The teacher watched the students cross the road.
老师看着学生过马路。
The boss made his workers work day and night.
→The workers were made to work day and night.
老板让他的工人没日没夜的工作。
△feel一词在使用to do型不定式作宾语补足语时,不带to;在使用to be型不定式时,要带to,如:
He felt them to be right.Did you feel the earth shake?
四 不定式作表语
1.主语和表语都是不定式（其含义往往一是条件,一是结果）,如:
To be kind to the enemy is to be cruel to the people.
To do that would be to cut the foot to fit the shoe.
2.主语是以aim,duty,hope,idea,intention,mistake,plan,proposal,job,suggestion等为中心词的名词词组,或是以what引导的名词性从句时,后面的表语不定式说明其内容,如:
My idea is to climb the mountain from the north.
Your mistake was not to write that letter.
My suggestion is to start work at once.
What I suggested is to start work at once.
注:在某些句型中,当主语部分有动作动词do时,作表语的不定式可以省略符号“to”,如:
All we have to do is push the button.
The only thing I can do now is go on by myself.
五 不定式结构作定语
1.位置和时间:不定式作定语通常只能放在被修饰的名词之后,时间一般是将来的时间。如:
She usually has a lot of meetings to attend in the evening.
I want to get something to read during the vocation.
John is always the first one to come to the factory.
2.不定式作定语时
(1)它与所修饰的名词存在逻辑上的动宾关系,如果不定式是不及物动词,它后面应加上必要的介词,如:
She has a lot of things to attend to.
The nurse has five children to look after.
(2)它若与主语存在逻辑上的主谓关系,作定语的动词不定式用主动形式表被动。若和主语没有主谓关系,要用被动形式。
I have a book to read.
Mother asked,"Have you any clothes to be washed,Tom?"
六 不定式作状语
不定式结构可以作状语,修饰动词、形容词、副词等,表示目的、原因、结果、条件等。
1.表示目的:
They ran over to welcome the delegates.
He bought a bicycle to go to town more quickly.
He went home to see his mother.
①:不定式结构表示目的时,通常句子的主语就是它的逻辑主语,但也有例外的情况,例如:
They sent a man to mend the window.
He stood up to be seen better.
②:为了强调表示目的的不定式,特别是在不定式结构前有否定词not时,通常可以在不定式符号to之前加上in order或so as,如:
He came here in order to see Charlie.
He shouted and waved so as to be noticed.
He went early in order not to miss the train.
I turned the radio down so as not to disturb him.
③:表示目的的不定式可以置于句首,这也是区别于其他功能的标志之一。但是,置于句首表示目的的不定式之前可以加上in order,但不可以加上so as,即in order to能放在句首,而so as to不能放在句首。如:
To draw maps properly,you need a special pen.
(In order to draw maps properly,you need a special pen.)
2.表结果:
He came round to find himself in hospital.
不定式结构表示结果更常见于下列句型:
①so…as to…
②such(…)as to…
③enough to…
④too…to…
注意:
（一）不定式所表示的结果往往含有“令人意想不到”的意味,其中以“使人不愉快的结果”较为常见。有时可以加上only或but only,以加强语气,如:
He got to the station only to be told the train had gone.
They lifted a rock only to drop it on their own feet.
(有时也可以表示令人愉快、惊喜的结果),如:
He went home to find his old friend Georgr waiting for him.
（二）不定式结构表示结果或表示目的,往往形式相似,这时,须根据词汇意义和语言环境认真加以区别,试比较:
He arrived late to find the others had gone home.
(=He arrived late and found the others had gone home.)
He arrived late to avoid meeting Robert.
(=He arrived late in order to avoid meeting Robert.)
动词不定式中注意的问题
1.(1)动词不定式的否定式只须在to前加not.
(2)带疑问词的动词不定式在to前加疑问词。
2.作简短回答或避免不必要的重复时,动词不定式常常省去to后面的动词,只保留to。
3.动词不定式的时态
(1)一般式(to do).
不定式的一般式所表示的动作（状态）和主句表示的动作是同时（或几乎同时）发生或之后发生。
(2)进行时(to be doing)
主句谓语动词表示的动作（情况）发生时,不定式所表示的动作正在进行。
(3)完成式(to have done)
动词不定式的动作发生在谓语动词表示的动作之前。
4.动词不定式的语态
(1)主动式(to do/to be doing/to have done)
当不定式的逻辑主语（主句的主语）是不定式所表示的动作的执行者时。
(2)被动式(to be done/to have been done)
当不定式的逻辑主语（主句的主语）是不定式所表示的动作的承受者时。