(一)不定式
非谓语动词有三种形式：不定式，动词ing形式(v-ing)及过去分词(ed分词)。
不定式的基本形式是由“to+ 动词原形”构成，其否定形式是not to do，不定式可以带自己的宾语或状语，构成不定式短语，没有人称和数的变化，但有时态和语态的变化，不定式在句中可作主语、表语、宾语、定语、状语、补足语，不作谓语。如：
Lucy asked him to turn up the radio.
To make a plan first is a good idea.
1. 动词不定式不失动词的特点，有时态和语态的变化，不定式有六种形式，以write为例：
主动态 被动态
一般式 to write to be written
完成式 to have written to have
been written
进行式 to be writing
完成进行式 to have
been writing
(1)不定式的时态：
①不定式所表达的动作与谓语动词同时发生或是在谓语动词之后发生，不定式用一般式，如：
It seems that he knows this.
鯤e seems to know this.
I hope that I'll see you again.
鯥 hope to see you again.
②不定式所表达的动作与谓语动词同时发生，并强调动作正在进行的情景，或持续性，不定式用进行式，如：
He pretended that he was listening to English course when I came in.
鯤e pretended to be listening to English course when I came in.
I am very glad that I am working with you.
鯥 am very glad to be working with you.
③不定式的动作发生在谓语动词之前，不定式用完成式，如：
I am sorry that I have put you so much trouble.
鯥 am sorry to have put you so much trouble.
It seems that I have met you somewhere before.
鯥 seem to have met you somewhere before.
④如果强调不定式所表示的动作从过去某一时刻起一直持续到某一时刻，不定式用完成进行时，强调动作的持续性，不强调结果。如：
She seems to have been reading the novel for three hours.
The rain was said to have been falling for a week.
(2)不定式的语态：当不定式的逻辑主语与不定式是被动关系时，不定式一般用被动式。如：
This is the plan to be discussed at today's meeting.
The novel is said to have been translated into several languages.
Whether most countries can use natural energy in future remains to be seen.
2. 不定式的作用
(1)不定式作主语：
To say is one thing; to do is another.
To read novels is my hobby.
it形式主语常常代替作主语的不定式，而将不定式或不定式短语放在后面。
To talk with him is a great pleasure.
鯥t is great pleasure to talk with him.
To make electricity by building a dam across the sea is possible.
鯥t is possible to make electricity by building a dam across the sea.
注意：①To see is to believe. 主语和表语都是不定式，不能用it代替：It is to believe to see是错误的。
②To answer correctly is more important than to finish quickly. 而finish与finishing放在than后面都是不合适的，因为前面句子的主语是to answer，后面的主语也要是to finish, 保持than前后句子结构平行。
(2)不定式作表语：不定式在系词后面作表语。
At that time his job was to write reports for the newspaper.
This suit doesn't seem to fit me.
The problems remain to be unsettled.
(3)不定式作宾语：在下列及物动词后，常跟不定式作宾语：want, need, hope, wish, expect, like, hate, try, manage, forget, remember, know, begin, start, intend, plan, mean, pretend, prefer, agree, refuse, learn等。
To keep the water clean, you need to get some under water plants.
I prefer to stay at home rather than go out.
They have decided to visit the nature park for the milu deer.
注意：不定式作宾语时，有时用“it”替换，it为形式宾语，而将真正的不定式作宾语后置，如：
I found to learn English well not easy.
鯥 found it not easy to learn English well.
I feel to help others my duty.
鯥 feel it my duty to help others.
(4)不定式作宾语补足语和主语补足语：通常用于及物动词或动词短语之后，如：
Jim told me to give his best wishes to everyone here.
What caused you to change your mind?
在被动语态was considered后面，不定式为主语补足语接不定式作宾补和主补的动词常有:
ask, beg, cause, call n, help, force, allow, permit, advise, order, get, want, wish, tell
等。
(其中没有hope sb. to do, suggest sb. to do和agree sb. to do)
注意：①不定式作宾语补足语，在部分感官及使役动词后，用不带to的不定式作宾语，常用的动词有：let, make, have, see, watch, notice, observe, look at, listen to, feel等，help有无to都可以，如：
The teacher had us recite the text every day.
The boss made his men work all the night.
把上面句子变成被动语态后，不定式成为句子的主语补足语，需带to，即在被动语态中不定式一律带to，不存在省略问题。
注意：②在谓语动词think, consider, suppose, believe, imagine, prove, find等后面跟to be作宾补，不跟to do，但其中有些可跟to have done作宾补。如：
imagine…to be
Imagine yourself(to be)in his place.
find…to be
We found him(to be)honest.
suppose…to be/suppose…to have done.
I suppose him to be about fifty.
We suppose him to have stolen it.
(5)不定式作定语：不定式作定语，有时与前面被修饰的名词逻辑上有动宾关系，如果不定式是不及物动词或所修饰的名词是不定式的地点，工具等，不定式后面须有相应的介词，如：
I have a meeting to attend. (attend the meeting)
及物动词+ 宾语
Pass me a piece of paper to write on. (write on the paper)
不及物动词+ 介词+ 宾语
在time, place, way后面的不定式省略介词，如：
He had no money and no place to live.
其他不定式作定语情况，如：
I have no chance to go abroad.
They had never moment to rest.
注意：there be句型中的不定式作定语用主动或被动都可以
There is a lot of work to do.
=There is a lot of work to be done.
There is no time to lose.
=There is no time to be lost.
但是在下列句子中，不定式主动与被动形式意义不同：
--Have you anything to wash?
--No, nothing. I plan to go shopping.
不定式动作的执行者是you. you wash something
--Have you anything to be washed?
--No, Thank you.
不定式动作的执行者不是you. 是省略了的(…to be washed)by me或by someone else.
不定式作状语：
①作目的状语：
I got up early in order to catch the 6∶30 train.
The boy ran all the way so as not to be late.
注意：so as to不能置于句首，in order to可以。
②作原因状语：
He smiled to think of his clever plan.
③在某些形容词后面作状语：
I am glad to see you.
You are sure to succeed.
④作结果状语：
第一, I hurried to the post office, only to find it closed. (出乎意料的结果)
第二，too…to…“太……以至于不……”(to后面译作否定)
He is too old to read.
The boy is too young to dress himself.
当不定式前的形容词为nervous, pleased, willing, delighted, happy, glad等时，too…to，“to…”可译作肯定，
They are too nervous to leave. 他们急于离开
当too前有only, 即only too…to译作肯定
I am only too pleased to help you.
当不定式前有否定意义的词时译作肯定
We are never too old to learn. 活到老，学到老。
第三，形容词/副词enough to do sth.
He was quick enough to catch the ball.
The girl is old enough to go to school.
第四，so…as to/such…as to如此……以致于……
He was so angry that he was unable to speak.
He was so angry as to be unable to speak.
He was such a fool that he believed the cheat.
He was such a fool as to believe the cheat.
⑤不定式作方面状语，不定式作方面状语与句子的主语构成逻辑上的动宾关系，不定式多用主动结构，如果不定式为及物动词，后面不必再跟宾语，如果不定式为不及物动词，要用相应的介词，如：
The mountain is difficult to climb. (动宾关系：climb the mountain)
不定式不说to climb it或to be climbed
Lesson Two is easy to learn. (动宾关系：learn Lesson Two)
有时由形容词+ to do结构一起做宾语补足语
3. 不定式的逻辑主语：不定式的逻辑主语一般是句子的主语，如He seemed to be reading something, 当需要明确指出不定式动作的执行者时，用for/of sb. (sth. )to do sth. 表示，如：
(1)当作表语的形容词表达不定式的逻辑主语的品行，性格，性质时，要用of，常见的这类形容词有:
brave, careful, careless, kind, nice, good, honest, clever, wise, unwise, stupid, foolish, rude, cruel, silly, thoughtful, impolite, polite, right, wrong, 等。这时It+ be+ 形容词+ of sb. /sth. to do sth. 句型，等于sb. /sth. + be+ 形容词to do sth. , 如：
It is very kind of you to say so.
相当于You are very kind to say so.
It is clever of him to win the competition.
鯤e is clever to win the competition.
It+ be+ 形容词+ for sb. /sth. to do sth. 这一句型中的形容词大多为：
easy, important, usual, difficult, hard, possible, impossible, necessary等。这些词只能说明不定式行为的是与非，不能说明不定式的执行者，所以不等于sb. + be+ 形容词+ to do sth. ，如：
1)It is difficult for beginners to read the book.
不能说：Beginners are difficult to read.
但是第一类，即It+ be+ 形容词+ of sb. to do sth. 句型中的形容词，如right, impolite…等如果强调评论人用of，强调评论行为也可用for，应用情况如下：
(1)当sb. 为泛指时，形容词着重评论不定式行为本身，如：
It was not right for the south to break away from the Union.
(2)当不定式为被动语态时，不定式的执行者常常省略，因此形容词只用来评论不定式行为了。
It was unkind for you to be laughed at.
总之for sb. to do sth. 强调不定式行为
of sb. to do sth. 强调不定式执行者
4. 带疑问词的不定式：动词不定式可以和疑问词what, which, how, where, when, whether等连用，构成不定式短语，如：
The question is when to start.
They haven't ageed on whether to build a factory here or not.
what to say.
I don't know what to write about.
how to do it.
注意：没有if to do和why to do.
I don't know why to do it. (误)
I don't know why I should do it. (正)
5. 不定式省略“to”的情况：
(1)当and或or连接同一概念的不定式时，或者当它们之间的关系并列一致时，可将and或or后面的to省去，如：
I'd like to go and see a film.
He had to have a job or go hungry.
但是，有时为了表示对照，或加强语气，则不可以省去to，如：
It is easier to say than to do.
(2)不定式在一部分感官或使役动词后面作宾补省略to。
(3)不定式在but(除了……以外)，except后面的使用，如果but, except前有行为动词do, but, except后省去to，如：
They had nothing to do but wait for the doctor.
The whole night he did nothing except watch TV.
(4)在固定句型中：would rather do…than do…/prefer to do rather than do:
1)The bus was so crowded that I'd rather walk home than take a bus.
2)I prefer to play tennis rather than(play)basketball.
6. “to”代表整个不定式：有时为了避免重复，省去不定式后面的内容，保留到不定式符号to, 如果是to be，保留到be，如：
--Will you please give him a message when you see him?
--I'll be glad to.
--Would you like to go shopping with me?
--I'd like to. (或I'd love to)
有时为了强调，也可以不省略。
Do what he or she tell you to do.
(二)动词-ing形式
动词-ing形式由动词原形+ ing构成。动词-ing形式起到名词、形容词和副词的作用，在句中可作主语、宾语、表语、状语和宾语补足语，但不能单独构成谓语，其构成形式如下，以do为例：
主动 被动
一般时态 doing being done
完成时态 having done having been done
否定式：not+ 动词-ing.
Learning English is very important to me.
Having been widened, the road took on a different look.
随着-ing在句子中所做的成分不同，所用的时态和语态有不同的要求，关于-ing的时态和语态的详细使用，在下面ing所作的句子成分中讲述。
1. 动词-ing形式作主语：
Seeing is believing.
有时主语太长，可用it作形式主语，将真正主语放在后面。如：
It is fun swimming in a river or lake in summer.
注意：动词-ing与不定式作主语的区别：
①一般情况下可以换用：
It is dangerous playing/to play with fire.
但在口语中用动词-ing形式放在句首比不定式多。
Going shopping is a pleasant thing.
②在下列句型中习惯用-ing作主语，不用不定式：
It is no use
It is no good doing.
It is useless
It is useless only learning English grammar.
It is no good cutting down the forest.
③在there+ be+ no+ 主语结构中，必须用动词-ing作主语：
There is no telling what will happen in the future.
④主语和表语结构相同，对等。
Seeing is believing.
To see is to believe.
2. 动词-ing作宾语：
(1)在及物动词后：
Would you mind my sitting here?
We suggest going out for a picnic on Sunday.
(2)在介词后：
We look forward to seeing you again.
(3)在worth, busy, feel like, look like等形容词后面：
China Daily is well worth reading.
The firefighters were busy putting out the big fire.
They look like winning the relay race.
Suddenly I feel like eating something.
动词-ing做主语或宾语时，一般情况下其逻辑主语为句子的主语，如果需要自己的逻辑主语时，要用物主代词或名词所有格+ 动词-ing，如：
His/Li Ping's coming late, made the teacher unhappy.
Would you mind my/me smoking here?
当动词-ing不在句首时，可用人称代词宾格，名词普通格代替，但逻辑主语为无生命的名词，或泛指时，用普通格，如：
We heard the noise of desks being opened and closed.
3. 不定式与动词-ing作宾语的比较：
(1)在下列一些动词后面常跟动词-ing作宾语，而不跟不定式：
admit, appreciate, advise, avoid, allow, consider, delay, dislike, enjoy, escape,
excuse, face, feel like, finish, fancy, forbid, forgive, imagine, include, keep, mention,
mind, miss, practice, resist, risk, suggest等。如：
He practices speaking English every day.
He admitted having broken the window.
I much appreciate your giving me the chance.
She dislikes doing housework.
He enjoys nothing but playing the computer.
(2)在下列一些动词后只跟不定式，不跟动词-ing作宾语：
want(想要)，hope, expect, wish, decide, would like, refuse, manage, pretend, demand,
offer, afford, plan, wonder, intend…等，如：
I am expecting to get a letter from my parents.
We are planning to build another research center.
I'd like to buy a new car made in the U. S. A.
(3)在下列一些动词后面跟不定式或动词-ing形式作宾语，意义不同，如：
I remember doing this exercise before.
我记得以前做过这个练习。
Remember to post the book for me.
记住帮我把那本书寄走。
归纳：remember doing记得(做过的事，某事已做过)
remember to do记住(去做某事，某事还没做)
We shall never forget hearing Jackson singing.
我们忘不了听杰克逊唱歌的情景。
Don't forget to give my regards to them.
别忘了代我向他们问好
归纳：forget doing忘了(做过的事，某事已做过)
forget to do忘了(去做某事，某事还没做)
I'll try to improve my pronunciation.
我要努力去纠正，提高我的发音。
Since no one answered the front door, why not try knocking at the back door?
既然前门没人答应，为什么不试试后门呢?
归纳：try to do. 尽力去做某事
try doing(用另外一种方法)试一试，试试看
I suggest we stop working and have a rest.
我建议我们停下干活，休息一会儿。
They stopped to listen, but there was no more sound.
他们停下来，听一听，再没什么声音。
归纳：stop to do停下(某事)去做某事，(表目的)
stop doing把某事停下来，(宾语)
What do you mean to do with your old bicycle?
你打算如何处理你那辆旧自行车?
I won't wait if it means delaying a week or so.
如果这意味着要推迟一星期左右，那我就不等了。
归纳：mean to do打算做某事
mean doing意味着做某事
(4)在love, like, hate, prefer后面跟不定式和动词-ing形式无多大区别，如：
Do you like to eat ice-cream?
I like traveling very much.
I like driving(do drive)fast cars.
(5)在start, begin后面，一般接不定式和动词-ing形式无多大区别，在下列情况下，多用不定式：
①自然界变化：
It started to rain.
Snow started to melt as spring came.
②心理活动，在understand, know, realize等词前面：
I began to understand my mother's feelings.
③begin, start本身为进行时：
Mother was starting to cook in the kitchen when I got home.
(6)在allow, advise, permit, forbid等动词后面，有名词或代词作宾语，用不定式做宾语补足语，如果没有宾语，直接用-ing形式，如：
1)We don't allow parking here.
2)The police don't allow people to park here.
3)He advised me to get an English pen friend.
4)I advise seeing more English films.
(7)need, require, want译作“需要”时，跟动词-ing作宾语，主动表示被动，相当于to be done，如：
The windows require cleaning.
The windows require to be cleaned.
The patient needs operating on at once.
The patient needs to be operated on.
The flowers want watering.
The flowers want to be watered.
(8)在一些固定表达中用动词-ing形式，不用不定式：
can't help doing, be worth doing, devote…to doing, look forward to doing, be/get/become used to doing, object to doing, thank…for doing, excuse…for doing等。
Einstein devoted his life to making a research in science.
I'm looking forward to getting your letter.
We are used to living in the countryside.
4. 动词-ing在句中作表语：
Our plan is setting up a new car factory.
My job is teaching/driving.
这类词作表语，起解释说明主语的作用，主表可颠倒：Teaching is my job. 转换成问句，用what提问：
--What's your job?
--My job is teaching.
这类词作表语，起描绘作用，主表不颠倒，转换成问句，用how提问
--How is your job?
--It is interesting.
--How was your trip?
--It is tiring, but interesting.
5. 动词-ing作定语：
(1)表示被修饰名词的用途：
There are two reading rooms in our school library.
a reading room其含义是A room is used for reading.
The swimming pool in our school is nearly completed.
the swimming pool其含义是The pool is used for swimming.
(2)如果动词-ing形式作定语表示被修饰的名词发出的一个正在进行的动作或某种特征行为，这时被修饰的名词与动词-ing逻辑上有主谓关系，如果是主动关系用doing, 被动关系用done, 或being done表达，另外有时间要求：
第一种情况：主动关系，-ing形式与谓语动词同时进行，或经常发生，用doing，如：
Look at the dancing girl. She is one of my classmates.
Look at the girl who is dancing. ….
China is a developing country.
China is a country that is developing.
注意：①如果动词-ing形式表示的动作发生在谓语动词之前，一般不用having done作定语，而用定语从句表达，如：
The teacher criticized the boy having broken the window. (误)
The teacher criticized the boy who had broken the window. (正)
注意：②如果表达的是未来发生的动作，或含有情态概念，用不定式表达，如：
I have a meeting to attend today.
鯥 have a meeting that I will attend today.
Mary is the proper worker to do the job.
鯩ary is the proper worker who can do the job.
第二种情况：被动关系：动词-ing表达的动作与谓语动词同时发生，正在进行，用being done; 发生在谓语动词之前，完成了的动作用done；发生在谓语动词之后，未来的动作，用to be done. 如：
The bridge being built now is two kilometers long.
鯰he bridge that is being built now is two kilometers long.
The bridge built last year is two kilometers long.
鯰he bridge that was built last year is two kilometers long.
The bridge to be built next year will be two kilometers long.
鯰he bridge that will be built next year will be two kilometers long.
6. 动词-ing作宾语补足语和主语补足语：经常在see, hear, feel, watch, notice,
observe, find, get, look at, listen to, keep, leave, send, set, catch等一些动词后面用动词-ing作补语，其中宾语和宾语补足语在逻辑上有主谓关系，如果主谓关系是主动的，又表示动作在进行，或状态的持续，用doing; 如果主谓关系是被动的，又表示动作在进行，用being done，如：
I noticed them repairing the car.
鯳hen they were repairing the car, I noticed.
I noticed the car being repaired.
鯳hen the car was being repaired, I noticed.
如果宾语和宾补是主动关系，又表示动作的全过程，即完成或一般时态，宾补用不定式to do表达(在某些动词后面不定式不带to)；如果是被动关系，又表示动作的全过程，即完成时态用done表达，如：
I often notice them repair the car.
I noticed the car repaired.
如果把上述句子变成被动语态，宾语补足语就变成主语补足语了。
7. 动词-ing形式作状语：动词-ing形式作状语时，要求其逻辑主语必须是句子的主语，句子的主语与动词-ing形式逻辑上有主谓关系。如果主谓关系是主动的，用主动语态；-ing动作与谓语动词同时发生用一般式doing, 如果-ing动作发生在谓语动词之前，用完成式having done, 如：
Walking along the street, I met a friend of mine.
相当于When I was walking along the street, I met a friend of mine.
Having finished their work, they had a rest. 相当于After they had finished their work, they had a rest.
如果主谓关系是被动的，用被动语态；-ing动作与谓语动词同时发生，用done；如果-ing动作发生在谓语动词之前，已完成的动作，用被动语态的完成式having been done, 如：
Having been cleaned and decorated, our classroom took on a new look.
相当于After our classroom had been cleaned and decorated, our classroom took on a new look.
Well known for his expert advice, he was able to help many people.
相当于As he is well known for his expert advice, he was able to help many people.
注意：-ing形式做状语时，如果-ing形式需要自己的逻辑主语，人称代词用主格，名词用普通格，如：
Mother/She being ill, he had to stay home to look after her.
It being Sunday, the shops are crowded.
(三)过去分词
过去分词由动词+ ed构成，起到形容词和副词的作用，在句中可作状语、表语、定语和宾语补足语。过去分词的性质是被动，完成，但有时侧重程度，有时侧重被动，不及物动词变成的过去分词无被动的意义，过去分词形式由动词原形加词尾-ed构成，及部分不规则的词如：done, played.
①侧重程度：
boiling water 沸水 fallen leaves落叶
boiled water 凉开水 frozen chicken冷冻鸡
developing country 发展中的国家
developed country 发达国家
②侧重主、被动：
a broken glass, a dancing girl, a damaged house.
1. 过去分词的作用：
(1)过去分词作状语：同动词-ing形式作状语一样，过去分词的逻辑主语是句子的主语，如是被动关系，又与谓语动词同时发生，或无一定时间对比，用过去分词，如：
Seen from the top of the mountain, the lake looks like a mirror. (相当于The lake is seen)
相当于When the lake is seen from the top of the mountain it looks like a mirror.
Heated, water can turn into vapor.
相当于If it is heated, water can turn into vapor.
(2)过去分词作表语：
We are interested in science.
(3)过去分词作定语：过去分词作定语，有时间要求，发生在谓语动词之前，即完成的动作，用done，而不用having been done.
The bridge built last year is 2 kilometers long.
People invited to the party are most scientists.
(4)过去分词作宾补：
I noticed the car repaired.
2. 过去分词与动词-ing形式的区别：
(1)作表语和定语的区别：动词-ing形式表示事物对人造成的影响，事物是主动的，常译成令人……，使人……；过去分词表示人对事物的看法产生的心理反应，人是被动的，常译作：感到……如：
The news is surprising.
We are surprised at the news.
这类词很多，如：inspiring, inspired, astonishing, astonished, tiring, tired,
moving, moved, disappointing, disappointed, worrying, worried, encouraging, encouraged, …….
(2)作宾补的区别：宾语与宾补逻辑上有主谓关系，主动用动词-ing或不定式表达，被动用being done或done表达。
We found him standing outside the door.
He found the door locked.
(3)作状语的区别：用作状语的动词，与句子的主语逻辑上有主谓关系、主动用-ing形式，被动用过去分词。
The boy entered the room, followed by a dog.
相当于The boy entered the room and he was followed by a dog.
The boy entered the room, following his father.
相当于The boy entered the room and followed his father.
(4)-ing形式与ed分词都可以作状语，表示时间、条件、原因、伴随、结果、让步、程度，如：
Having brought her father back to England, Lucy helped him to get better. (时间)
After she had brought her father back to England, Lucy helped him to get better.
Disturbed by the noise, we had to finish the meeting early. (原因)
We had to finish the meeting early because we were disturbed by the noise.
Born a free man, he was now in chains. (让步)
Though he was born a free man, he was now in chains.
(If) bitten by a snake, you should send for help and not walk. (条件)
鯥f you are bitten by a snake, you should send for help and not walk.
The boy ran in, carrying a ball in his arm. (伴随)
鯰he boy ran in and carried a ball in his arm.
He dropped the plate, breaking it into pieces. (结果)
鯤e dropped the plate and broke it into pieces.
(5)-ing形式与ed分词的否定式，由not+ -ing构成：
Not knowing how to do it, I asked him for help.