Doing作为非谓语的一种形式，它有两个身份：现在分词和动名词。同学们不必纠结于在使用时它是什么词，只需掌握doing 的6种成分和独立用法的结构就好。
1. 作主语:
（1）可以直接放在句首（这是常用的形式，也是常考点）
Seeing is believing. (眼见为实)
Saying is easier than doing.
（2）也可以用先行代词it作为形式主语（不常用），记住2个习惯表答法：
It is no use (good) 动名词：做某事没有用
e.g. It's no use crying over spilt milk. (覆水难收)
There is no 动名词 (= It is impossible to do sth.)
e.g. There is no knowing what may happen.（未来的事无法知道）
2.作表语：（2种情况）
（1）说明主语的内容
e.g. His hobby is collecting stamps. (此句为SVC结构) 可改为：Collecting stamps is his hobby.
注意它与谓语动词进行时的区别。
Cf. He is collecting stamps. (is collecting是谓语动词进行时，此句为SVO结构)
不能改为：Collecting stamps is he.
（2）表示心理状态的动词如excite，interest等都是及物动词，doing的形式的翻译是“令人激动的”、“令人高兴的”，主语或逻辑主语是物。
interesting 使人感到高兴
exciting令人激动的
delighting令人高兴的
disappointing令人失望的
encouraging 令人鼓舞的
pleasing令人愉快的
puzzling令人费解的
satisfying令人满意的
surprising令人惊异的
worrying令人担心的
如：Traveling is interesting but tiring.
3. 作宾语
A. 作动词的宾语:记住这几个只接doing 作宾语的动词（考点）
enjoy, mind, finish, appreciate, avoid, consider, delay, escape, pratise, suggest, keep(on), miss
He got well-prepared for the job interview, for he couldn't risk _____ the good opportunity.
A. to lose B. losing C. to be lost D. being lost
答案为B
彩蛋：
（1）有些动词（attempt, begin, continue, hate, like, love）后面既可以接不定式作宾语，也可以接动名词作宾语，意义差别不大。通常认为用动名词泛指一般的倾向性，用不定式则表示特定或具体某一种动作。
e.g. I like swimming but I don't like to swim in winter.
（2）动词prefer后面接不定式作宾语时，句子结构与接动名词作宾语是不一样。
e.g. I prefer to drive rather than to be driven.
I prefer driving to riding.
思考题：请翻译以上两个句子。
（3）有些动词，如forget, remember, regret等，后面接动名词表示的动作先于谓语动词动作，不定式表示的动作后于谓语动词。
e.g. When asked by police, he said that he remembered _____ at he party, but not ______.
A. to arrive, leaving B. to arrive, to leave C. arriving, leaving D. arriving, to leave
（4）在下列句型中动名词作真正宾语：
动词 it（形式宾语） 宾补 动名词（真正宾语）
e.g. I think it no use telling them.
We think it no good inviting to him.
B. 作介词的宾语 ：同学们只需记住介词to 的短语就好，因为其他的介词很容易辨别（考点和坑点）
look forward to 盼望， devote…to 致力于、献身于， be / get used to 习惯于 lead to 导致，get down to 着手做， pay attention to 注意 refer to 谈到、所指、参考，equal to 等于、能胜任，belong to 属于
4. 作补语
只有两类动词可以加doing作宾补:
1）感官动词：see hear watch feel notice observe find listen to look at 2）使役动词：have get make (可以用doing作宾补，但很少，也不是考点）
注意：doing作宾补,只能是用于这些词后,但是并不代表这些动词后的宾补形式都要用doing（有些后面可以加不带to的不定式作宾补）。
eg. I saw Thomas playing computer games .
Don’t have the students studying all day.
注意 ：宾语与作宾补的doing之间存在逻辑上的主谓关系，即宾语是doing动作的发出者。
5. 作定语
单个doing作定语时放在所修饰的名词前，短语doing作定语时放在后,一般都可以转化为一个进行时的定语从句。
e.g. a running boy = a boy who is running
an old man standing there = an old man who is standing there
a sleeping child = a child who is sleeping
也可表用途
swimming pool waiting room walking stick
a sleeping car=a car for sleeping
6. 作状语
doing作状语多表示时间、条件、原因、让步、结果、方式、伴随等。
Walking in the street, I saw him. (时间状语)
Working hard, you will succeed. （条件状语）
Being ill, she stayed at home. （原因状语）
Having failed many times, he didn’t lose heart. （让步状语）
His parents died, leaving him an orphan. （结果状语）
Please answer the question using another way. (方式状语)
He entered the classroom, taking a book in his hand. （伴随状语）
Note: doing作状语的形式都可以转化为状语从句，同学们可以试着把上面的句子转化一下。
7. 作同位语
e.g. That's the queen's full-time job, laying eggs. 这就是蚁后的专职工作--产卵。
2种独立用法（1）有些惯用的分词短语在句中可以没有逻辑上的主语而独立存在：（记住就好）
generally speaking一般来说 Judging from/by 由……判断出
strictly speaking 严格来说 roughly speaking 大致来说
narrowly speaking 狭义上说 broadly speaking 广义上说
（2）独立主格
独立主格结构（Independent Genitive）有两部分组成，前一部份是名词或者代词，后一部分是非谓语动词(不定式、动名词和分词)或形容词、副词、或介词短语。前后两部分具有逻辑主谓关系。独立主格结构在句中做状语，多用于书面语。 独立主格结构本身不是句子，在句子中作状语，表示时间、原因、条件、伴随、目的等。
e.g. Winter coming，it gets colder and colder． （it在句中指代的是”天气”）
Weather permitting, we will go outing this weekend.
练一练吧1.________in the queue for half an hour, Tom suddenly realized that he had left his wallet at home.
A. To wait B. Have waited C. Having waited D. To have waited
2.According to a recent U.S. survey, children spent up to 25 hours a week ______TV.
A. to watch B. to watch C. watching D. watch
3.The flu is believed _______ be viruses that like to reproduce in the cells inside the human nose and throat.
A. causing B. being caused C. to be caused D. to have caused
4.The flowers ______ sweet in the botanic garden attract the visitors to the beauty of nature.
A. to smell B. smelling C. smelt D. to be smelt
5.Don’t leave the water ______ while you brush your teeth.
A. run B. running C. being run D. to run
6.They see you as something of a worrier, ______ problems which don’t exist and crossing bridges long before you come to them.
A. settling B. discovering C. seeing D. designing
7.The news reporters hurried to the airport, only ______ the film stars had left.
A. to tell B. to be told C. telling D. told
8.You were silly not _____ your car.
A. to lock B. to have locked C. locking D. having locked
9.The man insisted _______ a taxi for me even though I told him I lived nearby.
A. find B. to find C. on finding D. in finding
10.The old man, _______ abroad for twenty years, is on the way back to his motherland.
A. to work B. working C. to have worked D. having worked
