非謂語動詞專題
不定式的用法：
1．作主語；不定式短語作主語時，往往放在謂語之后，用it作形式主語。
To see is to believe.
It’s right to give up smoking.
2．作表語；My job is to help the patient.
3． 作賓語；有些動詞后只能用動詞不定式作賓語，如：afford, agree, ask, decide, desire, expect, fail, hope, manage, promise, pretend, plan, intend, refuse, wish等。
4．作賓補；動詞不定式作動詞feel, hear, see, watch, notice, observe等感官動詞以及have, let, make等使役動詞后面的賓語補足語時，不定式to符號要省略。但如果這些句子變成被動結(jié)構(gòu)時，就必須帶to符號。如：
I often hear him sing the song.
He is often heard to sing the song.
注意： 動詞不定式在介詞but后面時， 如果介詞之前有行為動詞do的各種形式，那么，這些介詞后的不定式不帶to，否則要帶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．作定語；1）. 作定語的不定式如果是不及物動詞，或者不定式所修飾的名詞或代詞是不定式動作的地點，工具等，不定式后面須有相應(yīng)的介詞。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，不定式所修飾的名詞如果是time,place或way時，不定式后面的介詞習(xí)慣上省去。如：
He had no and no place to live.
We found a way to solve this problem.
2）. 當(dāng)作定語的不定式所修飾的名詞或代詞是不定式動作的承受者時，不定式既可以用主動語態(tài)，也可用被動語態(tài)，但其含義有所不同。試比較：
Have you anything to send? / Have you anything to be sent?
3）. 不定式作定語的幾種情況：
a.作后置定語可表將來：The meeting to be held tomorrow is very important.
b.用來修飾被序數(shù)詞，最高級等限定的中心詞：
He was the best man to do the job.
She was the first woman to win the gold medal in the Olympic Games.
c.用來修飾的詞是抽象名詞時，常見的有：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．作狀語；表目的，原因，結(jié)果或條件。如：
I came here to see you.(目的)
He hurried to the school to find nobody there.(結(jié)果)
To look at him, you would like him.(條件)
在某些形容詞作表語，表示喜，怒，哀，樂后跟不定式表原因。如：
We were very excited to hear the news.
在帶有enough或too的句子里，也常用不定式作狀語，表示程度。
He is old enough to go to school.
She is too tired to do the job.
注意：目的狀語還可以用in order to或so as to來表示但so as to不能置于句首。
7．作獨立成分；如：
To tell you the truth, I have got no money about me.
To be honest, I know nothing about it.
不定式與疑問詞who, which, when, where, how, what等連用，在句中起名詞作用，可充當(dāng)主語，表語，賓語等。如：
He didn’t know what to say.(賓語)
When and where to hold the meeting is not known yet.(主語)
My question was how to get so many books.(表語)
注意句型：Why not do sth.? Why do sth.?
不定式的主動(to do )和被動(to be done)
判斷不定式是主動還是被動，關(guān)鍵看不定式中的動詞與主句的主語之間的關(guān)系，主動即用“to do”，被動即用“to be done”; 如果與主句主語之間沒有關(guān)系，則看其與邏輯主語之間的關(guān)系，如果是被動，則用“to be done”.試比較：
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.（叫別人洗衣服）
3) There are five pairs (for you) to choose from. (暗含主語you)
不定式的時態(tài)
to do/to be doing/ to have done
He pretended to be reading a book when she went in. (動作正在進行)
I’m sorry to have kept you waiting.(不定式動作發(fā)生在謂語動詞之前)
不定式符號to的保留問題
有時為了避免重復(fù)，可以用來代替前面的不定式，這種情況常出現(xiàn)在下列動詞后：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.
動詞-ing形式的用法(過去分詞):
1. 動詞-ing形式作主語
Seeing is believeing.
Tom’s coming is what we have expected.
-ing或不定式都可以在句中作主語，但在下列句型中常用-ing作主語
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．動詞-ing形式作表語
Her job is washing, cleaning and taking care of the children.
3．動詞-ing形式作賓語
以下動詞或動詞詞組后面只接動名詞作賓語：admit, appreciate, avoid, consider(考慮), 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). 有些動詞或動詞詞組既可以跟動名詞作賓語，也可以跟不定式作賓語，但意義上有區(qū)別，要特別注意。如：
forget to do/doing; remember; regret; try; mean; stop; go on; can’t help等。
2). 在動詞等動詞后直接跟動詞形式作賓語，如果后面有名詞或代詞作賓語，其后用動詞不定式作賓語補足語。如：
allow/advise/forbid/permit doing sth./ sb to do sth.
3). need, want, require其后必須用動名詞的主動形式或不定式的被動形式作賓語，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．動詞-ing形式作定語（過去分詞作定語）
前置定語：He asked an embarrassing queation.
后置定語：A little child learning to walk often falls.
= A little child who learns to walk often falls.
注意：動詞-ing和過去分詞的區(qū)別---現(xiàn)在分詞表示主動含義或動作正在進行，過去分詞表示被動含義或動作已經(jīng)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．動詞-ing形式作狀語（過去分詞作狀語）
分詞作狀語時，分詞的邏輯主語必須與句子的主語保持一致。
分詞或分詞短語作狀語時，可以表時間，原因，結(jié)果，條件，讓步，行為方式，伴隨狀況等。表示時間關(guān)系的分詞短語有時可由連詞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.
現(xiàn)在分詞和過去分詞的時態(tài)與語態(tài)
一般式doing/done
完成式having done/ having been done
進行式being done
否定式是not+分詞短語
獨立成分作狀語
有些分詞短語，其形式的選擇不受上下文的影響，稱作獨立成分。常見的有：
Generally speaking,
Frankly speaking,
Judging from/by,
Considering,
Given,
責(zé)任編輯：李芳芳