现在分词doing用法讲解

注②：动名词作主语与不定式作主语的区别：
动名词作主语通常表示抽象的或泛指的动作，一般不与特定的
动作执行者联系在一起；不定式作主语通常表示具体的动作或行为，
往往与特定的动作执行者联系在一起，如：
It’s no use crying over spilt milk. (抽象) He realized that to go on like this was no use. (具体) 在实际运用中，一般可以互换，差异不大。但在下列几种情况
Our duty is serving the people heart and soul.
The situation is encouraging. This cake is very inviting.
The volleyball match we watched was very exciting.
动 名 词
一、动名词的形式
主动形式 被动形式
一般式
完成式
doing
having done
being done
having been done
二、功能及用法
1．动名词（短语）做主语，如： Writing the book has taken up all his spare time. Seeing is believing. 注①：动名词（短语）做主语还常用于下列结构： a. It’s no use sending him over. It’s too late already. It’s no good talking a lot without doing anything.
注②：动名词作表语与现在分词作表语的区别： 动名词作表语时相当于名词，说明主语的含义及内容，它与主语 是同等关系，主语与表语互换位置不影响句子的基本含义，但不可
用副词来修饰。
现在分词作表语时相当于形容词，说明主语的特征、性质、状态 等，主语与表语不可互换位置，但可用very, quite等副词来修饰， 如： My job is looking after the children.
中不能互换：
a. 当表语是动名词时，主语也要用动名词；当表语是不定式时， 主语也要用不定式，如： Seeing is believing.
To see is to believe.
b. 动名词和不定式作主语，一般都可以使用形式主语it，而将动名 词或不定式放在句尾。但是在下列句型中，一般宜用动名词，不宜 用不定式来代替： It’s no use doing … It’s no good doing… It’s a waste of time doing … 例如： It’s no use going there today; he won’t be at home. It’s a waste of time arguing about it. It’s no good waiting here. Let’s walk home. 而在It’s important … / It’s necessary … / It’s advisable … / It’s essential … / It’s fitting … 这类句型中，只能用不定式，如： It’s important to learn foreign languages. It’s quite necessary to read it many times.
4．动名词（短语）可以和about, against, at, before, after, by, for, besides, from, in, on, upon, without等介词构成短语，在句中作状语， 如： They broke in loud cheers on hearing the news. He warned me against swimming there. She left without saying good-bye to us. Besides cooking and sewing, she had to take care of the children. He felt uncomfortable about accepting the gift. They were surprised at your doing that. 5．动名词（短语）可以和介词构成短语作定语，如： He hasn’t much experience in running factories. What’s their reason for cancelling the English evening? Have you any objection to going there on foot? He has little hope of passing his examinations. They don’t approve of his way of looking at things. I’m glad to have this opportunity of coming to visit your country.
It’s a waste of time arguing about it.
b. There’s no joking about such matters. There’s no saying what he’ll be doing next. There’s no telling what he’s going to do.
★ 动名词（短语）还常常跟在短语动词之后，作介词的宾语。常 见的有： insist on / think of / dream of / object to / hear of / prevent … from / keep … from / stop … from / feel like / be engaged in / look forward to / depend on / thank … for / excuse … for / devote … to / set about / spend … in / get (be) used to … / be fond of / be afraid of / be tired of / succeed in / be interested in / be proud of / burst out / give up 等， 如： He insisted on seeing us home. They all objected to putting the meeting off. Are you interested in going to the show? I’m thinking of going to town this afternoon. I don’t feel like eating anything. She is afraid of falling behind the others. He finally got tired of doing office work. She devotes hours to helping Mother with housework on Sunday.
B. 在need, want, deserve等后，可用动名词的主动式表示被动含 义，或用不定式的被动式，意义上无差别。但用动名词较为普遍， （这时主语一般是物），如： The door needs oiling / to be oiled. C. 有的动词尽管可以用两种结构，但意义明显不同，须认真加以 区别： I forgot to close the door before I left the room. I forgot having closed the door. He tried to write better. (尽量努力地写) He tried writing with a brush. (用毛笔试着写) I couldn’t help finishing it. (不能不结束某事) I couldn’t help to finish it. (不能帮助结束某事) They left off fishing. (停止钓鱼) They left off to fish. (离开某处出发去钓鱼) I regret to say that there is no wine in the bottle. (对现在要发生的 事表示遗憾、抱歉) I regret not taking your advice. (后悔)
2．动名词（短语）作表语，如： Their job is building houses. His job is raising pigs. 注①：动名词作表语与不定式作表语的区别：
动名词作表语时表示比较抽象的一般行为、习惯；不定式作表
语时表示具体的某一次动作，特别是将来的动作，试比较： My favourite sport is swimming. The first thing for us to do is to improve our pronunciation.
上述动词尽管可以带两种结构作宾语，但用法不尽相同，需要 注意下列几个情况： A. 在begin, start, cease, continue, cannot bear, hate, like, love, prefer, propose 等动词后，两种结构意义无大的出入，如： She can’t bear being laughed at / to be laughed at. 但是在下列情况下，通常用不定式： a. 在would like / love / prefer / hate 后表示一个特定的新动作时： I’d like to buy a suit. I’d hate to disappoint them. b. 当谓语动词已用进行时态时： The water is beginning / starting to boil. I’m starting to work on my essay next week. c. 在begin 等后，非限定动词由某些状态动词构成时（即：指心理 状态或精神活动时）： She began to believe his story. He began to realize that he was wrong. d. 当主语是物，不是人时： The water started / began to boil. The ice started / began to melt.
3．动名词（短语）用作宾语的情况很多，如： Hearing the words, she couldn’t help thinking of her past bitterness. We all avoided mentioning that matter. ★ 能用动名词作宾语的动词有两类： 一类是只能用动名词作宾语的动词，其中有：avoid, admit, consider, delay, advise, diive up, can’t help, imagine, keep (on), don’t mind, miss, practise, put off, stop, go on, resist, suggest等，如： Mary is considering changing her job. I enjoy working with you. Would you mind ringing me up tomorrow? 另一类是既可以用动名词，又可以用不定式作宾语的动词，其 中有：begin, cannot bear, continue, forget, hate, intend, like, love, plan, prefer, propose, regret, remember, start, try, want, need, can’t afford等。