非谓语动词专题
不定式的用法：
1．作主语；不定式短语作主语时，往往放在谓语之后，用it作形式主语。
To see is to believe.
It’s right to give up smoking.
2．作表语；My job is to help the patient.
3． 作宾语；有些动词后只能用动词不定式作宾语，如：afford, agree, ask, decide, desire, expect, fail, hope, manage, promise, pretend, plan, intend, refuse, wish等。
4．作宾补；动词不定式作动词feel, hear, see, watch, notice, observe等感官动词以及have, let, make等使役动词后面的宾语补足语时，不定式to符号要省略。但如果这些句子变成被动结构时，就必须带to符号。如：
I often hear him sing the song.
He is often heard to sing the song.
注意： 动词不定式在介词but后面时， 如果介词之前有行为动词do的各种形式，那么，这些介词后的不定式不带to，否则要带to。另外，在can’t choose but和can’t help but等后面的不定式也省略to。如；
We could do nothing but wait.
We have no choice but to wait.
5．作定语；1）. 作定语的不定式如果是不及物动词，或者不定式所修饰的名词或代词是不定式动作的地点，工具等，不定式后面须有相应的介词。如：
There is nothing to worry about.
The Browns have a comfortable house to live in.
Please give me a knife to cut with.
但是，不定式所修饰的名词如果是time,place或way时，不定式后面的介词习惯上省去。如：
He had no and no place to live.
We found a way to solve this problem.
2）. 当作定语的不定式所修饰的名词或代词是不定式动作的承受者时，不定式既可以用主动语态，也可用被动语态，但其含义有所不同。试比较：
Have you anything to send? / Have you anything to be sent?
3）. 不定式作定语的几种情况：
a.作后置定语可表将来：The meeting to be held tomorrow is very important.
b.用来修饰被序数词，最高级等限定的中心词：
He was the best man to do the job.
She was the first woman to win the gold medal in the Olympic Games.
c.用来修饰的词是抽象名词时，常见的有：ability, chance, idea, fact, answer, reply, attempt等。如：
Do you have the ability to read and write English?
I have no chance to go sightseing.
6．作状语；表目的，原因，结果或条件。如：
I came here to see you.(目的)
He hurried to the school to find nobody there.(结果)
To look at him, you would like him.(条件)
在某些形容词作表语，表示喜，怒，哀，乐后跟不定式表原因。如：
We were very excited to hear the news.
在带有enough或too的句子里，也常用不定式作状语，表示程度。
He is old enough to go to school.
She is too tired to do the job.
注意：目的状语还可以用in order to或so as to来表示但so as to不能置于句首。
7．作独立成分；如：
To tell you the truth, I have got no money about me.
To be honest, I know nothing about it.
不定式与疑问词who, which, when, where, how, what等连用，在句中起名词作用，可充当主语，表语，宾语等。如：
He didn’t know what to say.(宾语)
When and where to hold the meeting is not known yet.(主语)
My question was how to get so many books.(表语)
注意句型：Why not do sth.? Why do sth.?
不定式的主动(to do )和被动(to be done)
判断不定式是主动还是被动，关键看不定式中的动词与主句的主语之间的关系，主动即用“to do”，被动即用“to be done”; 如果与主句主语之间没有关系，则看其与逻辑主语之间的关系，如果是被动，则用“to be done”.试比较：
1) I have some clothes to wash, so I can’t go out now.(自己洗衣服)
2) Are you free now? I have some clothes to be washed.（叫别人洗衣服）
3) There are five pairs (for you) to choose from. (暗含主语you)
不定式的时态
to do/to be doing/ to have done
He pretended to be reading a book when she went in. (动作正在进行)
I’m sorry to have kept you waiting.(不定式动作发生在谓语动词之前)
不定式符号to的保留问题
有时为了避免重复，可以用来代替前面的不定式，这种情况常出现在下列动词后：expect, prefer, care, mean, forget, want, wish, hope, try以及be glad/happy;would like/love等后。
I have’t been to Hong Kong, but I wish to.
---- Are you on holiday?
---- No, but I’d like to be.
---- I didn’t tell him the news.
---- Oh, you ought to have.
动词-ing形式的用法(过去分词):
1. 动词-ing形式作主语
Seeing is believeing.
Tom’s coming is what we have expected.
-ing或不定式都可以在句中作主语，但在下列句型中常用-ing作主语
It’s no use/good+doing sth./ It’s of little use/good+doing sth.
It is no use crying over spilt milk.
It is of little good staying up too late every day.
2．动词-ing形式作表语
Her job is washing, cleaning and taking care of the children.
3．动词-ing形式作宾语
以下动词或动词词组后面只接动名词作宾语：admit, appreciate, avoid, consider(考虑), delay, enjoy, imagine, suggest, finish, mind, practise, resist, give up, feel like, keep on, insist on, look forward to, stick to, get down to等。
注意：1). 有些动词或动词词组既可以跟动名词作宾语，也可以跟不定式作宾语，但意义上有区别，要特别注意。如：
forget to do/doing; remember; regret; try; mean; stop; go on; can’t help等。
2). 在动词等动词后直接跟动词形式作宾语，如果后面有名词或代词作宾语，其后用动词不定式作宾语补足语。如：
allow/advise/forbid/permit doing sth./ sb to do sth.
3). need, want, require其后必须用动名词的主动形式或不定式的被动形式作宾语，表示事情需要做。如：
Sth. need/requie/want doing=to be done
Sth. be worth doing
Sth. be worthy of being done=be worthy to be done
4．动词-ing形式作定语（过去分词作定语）
前置定语：He asked an embarrassing queation.
后置定语：A little child learning to walk often falls.
= A little child who learns to walk often falls.
注意：动词-ing和过去分词的区别---现在分词表示主动含义或动作正在进行，过去分词表示被动含义或动作已经完成。如：
falling leaves/fallen leaves
boiling water/boiled water
a puzzling look/a puzzled look
Those inviting me to attend the meeting are my friends.
=Those who invite me to attend the meeting are my friends.
Those invited to the meeting are all the top leaders from different countries.
=Those who are invited to the meeting are all the top leaders from different countries.
5．动词-ing形式作状语（过去分词作状语）
分词作状语时，分词的逻辑主语必须与句子的主语保持一致。
分词或分词短语作状语时，可以表时间，原因，结果，条件，让步，行为方式，伴随状况等。表示时间关系的分词短语有时可由连词while或when引出。如：
Given more attention, the trees could have grown better.
Followed by some officials, the leader inspected his army.
Following their teacher, the students went into the classroom.
Being sick, I stayed at home.
Having finished his homework, he went on to watch TV.
Having been told many times, he still repeated the same mistake.
He sat in the armchair, reading the newspaper.
Not hearing from him, I give him a phone call.
When leaving the airport, they waved to us constantly.
现在分词和过去分词的时态与语态
一般式doing/done
完成式having done/ having been done
进行式being done
否定式是not+分词短语
独立成分作状语
有些分词短语，其形式的选择不受上下文的影响，称作独立成分。常见的有：
Generally speaking,
Frankly speaking,
Judging from/by,
Considering,
Given,
责任编辑：李芳芳