當doing形式做名詞時，我們稱之為「動名詞」；做謂語動詞或形容詞，副詞時，我們稱之為「現在分詞」
一、doing形式作主語，是動名詞
Talking mends no holes. 空談無濟於事。
Talking to him is talking to a wall. 和他談話是在對牛彈琴。
Fighting broke out between the South and the North.
南方與北方開戰了。
Playing computer games is a waste of time.玩電子遊戲是浪費時間。
註：動名詞做主語和不定式做主語一樣，也可以用it作形式主語。
常見用法有it's no good, it's no use, it's not worth如：
It's not worth taking an umbrella. It's not going to rain.
沒必要帶把傘。不會下雨的。
It's no use crying over spilt milk. 覆水難收。
It's rather tiring walking around in a city.
在城市裡走來走去是相當累人的。
二、doing形式作賓語，是動名詞
1．有些動詞（尤其是與感情或觀點有關的動詞）或短語動詞後常用動名詞作賓語。如admit, deny, appreciate, avoid，can't stand（不能忍受）, consider，dislike，enjoy，escape, excuse, feel like, finish, forgive, imagine, fancy, keep, mention, mind, miss（錯過）, practice, can't help, involve, keep, mean, risk, suggest等等。
Having a healthy lifestyle involves following a balanced diet which means eating a variety of fruit and vegetables and avoiding too many sweet or fatty foods, and also taking regular exercise.
有一個健康的生活方式涉及到均衡的飲食，這意味著吃各種水果和蔬菜，避免過多的甜食或脂肪的食物，並採取定期運動。
Doing morning exercises is good for your health.
做早操對你的健康有好處。
Do you want to come swimming / sailing / running with us?
你想和我們一起遊泳/划船/跑步嗎？ They've gone shopping.
他們去購物了。
I have finished writing this book.
我已經寫完這本書了。
He admitted taking the money.
他承認錢是他拿的。
注意: 當need, want, require, worth後面接doing也可以表示被動。
Your hair wants cutting.
你的頭髮該理了。
The floor requires washing.
地板需要衝洗。
Her shoes wants mending.
她的鞋該修理了。
2. 介詞後跟動名詞做賓語I spent my time (in) swimming and sunbathing.
我把時間花在遊泳和日光浴上。 Anna spent a lot of time (in)researching her project.
安娜花了很多時間研究她的項目。 Are you interested in joining a tennis club?
你有興趣參加網球俱樂部嗎？ I must apologize for arriving late.
我必須為遲到而道歉。 I am not used to driving on the left.
我不習慣靠左邊開車。
3. 有些動詞既跟動名詞doing作賓語，也跟動詞不定式to do作賓語，但一般表達的意思有區別：
1）在begin, continue, love, like, hate, prefer, intend, start後用動名詞
和用不定式作賓語均可，意義沒有多大區別。
2）動詞forget, go on, mean, regret, remember, stop, try, can't help後
跟動名詞和跟不定式區別較大，須注意。
forget, regret, remember後跟動名詞，動名詞表示已經發生的動作；
跟不定式表示將要發生的動作。
go on doing 繼續做原來做的事 go on to do 接著做另一件事
mean doing 意味著要做某事 mean to do 想要做某事
stop doing 停止做某事 stop to do 停下（別的事）開始做某事
try doing 試著做某事 try to do 努力做某事
can't help doing 禁不住做某事
can't help to do 不能幫助做某事
三、doing形式作定語，動名詞或現在分詞
1. 表示被修飾者的作用或功能，為動名詞（或者說，被修飾詞和doing表達的動作沒有主謂關係）
building materials = materials for building 建築材料
drinking water = water for drinking 飲用水
a walking stick = a stick for walking 手杖
a reading room = a room for reading 閱覽室
a writing desk = a desk for writing 寫字檯
tiring music = music that is tiring 煩人的音樂
a surprising result 一個驚人的結果
表示被修飾者的動作,是現在分詞。（或者說，被修飾詞和doing表達的動作是主謂關係）如：
the running sheep
奔跑的綿羊
a crying baby
大哭的嬰兒
They lived in a room facing the street.
他們住在一間面朝街的房子。
The man standing there is Peter’s father.
站在那兒的那個人是彼得的父親。
Anybody swimming in this river will be fined.
在這條河裡遊泳的任何一個人都會被罰款。
四、doing形式作表語，動名詞或現在分詞
doing形式作表語時放在系動詞之後，用來泛指某種動作或行為，以說明主語的身份、性質或情況。
動名詞，就是動詞名詞化，所以他是關注的是其名詞性，如：
seeing is believing.
眼見為實
Her hobby is painting.
她的業餘愛好是畫畫。
My job is looking after the children.
我的工作就是照顧這些孩子。
現在分詞作表語，表達的是主語所具有的特徵，如：
The film is so exciting.
這部電影真精彩。
His concern for his mother is most touching.
他對母親的關愛很感人。
She was very pleasing in her appearance.
她外表很討人喜歡。
五、doing形式作賓語補足語，是現在分詞
1. 現在分詞作賓語補足語常放在賓語後面，表示一個正在進行的主動性的動作，強調一個過程或一種狀態。如：
When we returned to the school, we found a stranger standing at the entrance.
當我們回到學校時, 發現一個陌生人站在大門口。
We found the snake eating the eggs.
我們發現蛇正在吃雞蛋。
I found a bag lying on the ground.
我發現地板上放著一個包。
The boss kept the workers working the whole night.
那老闆讓工人整夜地工作。
2. 當主句轉換為被動結構時, 原來作賓語補足語的動詞-ing形式便轉換為主語補足語。如：
They found the result very satisfying.
= The result is found very satisfying.
這個結果很令人滿意。
They heard him singing in the next room.
= He was heard singing in the next room.
有人聽到他在隔壁房間唱歌。
We mustn’t keep them waiting.
= They mustn’t be kept waiting.
千萬不能讓他們等。
六、doing形式作狀語，是現在分詞
The dog entered the room, following the boy.
這條狗跟著男孩進了屋。（現在分詞作伴隨狀語，表主動。）
Judging from his expression, he doesn't know the news.
從表情上來看，他還不知道這個消息。（用現在分詞作狀語）
I'd like to stay here for another week enjoying the beautiful scenery here.
我想在這兒多待上一周，欣賞一下這兒的美景。（現在分詞作伴隨狀語）
Not knowing how to work out the difficult physics problem, he asked the teacher for help.
因為不知道如何解這道物理難題，他求助老師。（現在分詞短語作原因狀語）
Having lived with the girl for 5 years, we all know her very well. = Because we have lived with the girl for 5 years, we all know her very well.
因為與那個女孩一起生活了五年，我們都非常了解她。（現在分詞短語作原因狀語）
They closed the door, there being no customers
他們的店關門了，因為沒有顧客。（現在分詞短語作原因狀語）
Working hard, you'll succeed. = If you work hard, you'll succeed.
如果你努力工作，你會成功的。（現在分詞短語作條件狀語）
Their car was caught in a traffic jam, thus causing the delay.
他們的車遇上交通阻塞，因而耽誤了。（現在分詞短語作結果狀語）
圖片來自網絡，版權為原作者所有