一、名词定义
动名词是非限定动词的一种形式,由动词原形+ing构成。它既有动词的特征,又有名词的特征,故称。动名词也有时态和语态的变化,如表所示(以及物动词write为例),不及物动词没有语态的变化。
时态/语态
主动
被动
一般式
writing
being written
完成式
having written
having been written
二、动名词的作用
由于动名词是由动词变化而来,它仍保留着动词的某些特征,具有动词的某些变化形式,用以表达名词所不能表达的较为复杂的意念。动名词的名词特征表现在它可在句子中当名词来用,作主语、宾语、表语、定语。它也可以被副词修饰或者支配宾语
1、作主语
例如:
Reading is an art. 读书是一种艺术。
Climbing mountains is really fun. 爬山真是有趣
  Working in these conditions is not a pleasure but a suffer. 在这种工作条件下工作不是一件愉快的事而是一件痛苦的事。
  动名词作主语,在动词的基础上加Ing,是该动词或动词短语,有名词的各种特征,可作名词灵活使用。如:
  It is no use/no good crying over spilt milk. 覆水难收
  It was hard getting on the crowded street car. 上这种拥挤的车真难。
  It is fun playing with children. 和孩子们一起玩真好。
  There is no joking about such matters. 对这种事情不是开玩笑。
  动名词作主语的几种类型
  动名词可以在句子中充当名词所能充当的多种句子成分。在这里仅就动名词在句子中作主语的情况进行讨论。
  动名词作主语有如下几种常见情况:
  〈1〉 直接位于句首做主语。例如:
  Swimming is a good sport in summer.
  〈2〉 用 it 作形式主语,把动名词(真实主语)置于句尾作后置主语。
  动名词做主语时,不太常用 it 作先行主语,多见于某些形容词及名词之后。例如:
  It is no use telling him not to worry.
  常见的能用于这种结构的形容词还有:better,wonderful,enjoyable,interesting,foolish,difficult,useless,senseless,worthwhile,等。
  注意:important,essential,necessary 等形容词不能用于上述结构。
〈3〉 用于“There be”结构中。
例如:
  There is no saying when he'll come.很难说他何时回来。
〈4〉 用于布告形式的省略结构中。
例如:
  No smoking ( =No smoking is allowed (here) ). (禁止吸烟)
  No parking. (禁止停车)
〈5〉动名词的复合结构作主语
当动名词有自己的逻辑主语时,常可以在前面加上一个名词或代词的所有格,构成动名词的复合结构(——这时,名词或代词的所有格做动名词的逻辑主语)。动名词的复合结构也可以
在句中作主语。
例如:
suggest的名词
  Their coming to help was a great encouragement to us.
  .例词
  shopping 、fishing 、cycling这些都是很常见的动名词 
〈6〉动名词作主语与动词不定式作主语的比较
  动词不定式和动名词都可以用作主语。在意义上相近。但动名词多用来表示泛指或抽象动作,不定式多用来表示特指或具体动作。比较:
  Smoking is not good for health.
  It is not good for you to smoke so much.
  注意:
〈1〉在口语中,用动名词作主语位于句首的较不定式多见。
〈2〉在“It is ”,“It is ”,“It ”,“It is a waste ”等句型中,通常用动名词作真实主语:
  It is no use/good/a waste of time talking about that.
It is no use/good/a waste of time to talk about that.
〈3〉在疑问句中,通常用动名词的复合结构,而不用不定式的复合结构作主语:
  Does your saying that mean anything to him?
 Does for you to say that mean anything to him?
〈4〉在“There be”句型中,只能用动名词,而不能用不定式作主语:
  There is no telling what will happen.
  It is impossible to tell what will happen.
〈5〉当句子中的主语和表语都是非限定动词时,要遵循前后一致的原则,主语和表语在形式上要求统一:
  Seeing is believing.
  *To see is to believe.
2、作宾语
  某些动词后出现非限定性动词时只能用动名词作宾语,不能用不定式。常见的此类动词有:advise, allow, permit, avoid, consider, enjoy, finish, give up, cannot help, imagine, include, keep, keep on, mind, miss, put off, delay, practise, resist, suggest, depend on, think about, set about, succeed in, worry about, burst out, insist on, can’t stand, be used to, get used to, devote…to…, look forward to, pay attention to, get down to,escape 等。如:
  They went on walking and never stopped talking.
  他们继续走,说个不停。
  I found it pleasant walking along the seashore.
  在海滩上走真是乐事。
  Mark often attempts to escape being fined whenever he breaks traffic regulations.
  每当马克违反交通规则时,他常常企图逃避的处分。
  (2)作介词的宾语
  We are thinking of making a new plan for the next term. 我们正考虑为下学期制定新的计划。
  Shall we have a rest or get down to doing our work? 我们休息呢还是开始干活?
  (3)作形容词的宾语
  The music is well worth listening to more than once. 这种曲子很值得多听几遍。
  We are busy preparing for the coming sports meet. 我们正为马上到来的运动会忙着做准备。
3、作表语
作表语,对主语说明、解释。例如:
Her job is washing, cleaning and taking care of the children. 她的工作是洗刷、清扫和照顾孩子。
比较:She is washing, cleaning and taking care of the children.
  动名词作表语时句子主语常是表示无生命的事物的名词或what引导的名词性从句。表语动名词与主语通常是对等的关系,表示主语的内容,主语、表语可互换位置。
  Your task is cleaning the windows. 你的任务就是擦窗户。(Cleaning the windows is your task.)
  What I hate most is being laughed at. 我最痛恨的就是被别人嘲笑。 (Being laughed at is what I hate most.)
4、作定语
作定语,一般表示所修饰名词事物的用途。
例如:
a writing desk=a desk for writing 写字台
a swimming pool=a pool swimming 游泳池
有些动名词作定语,与所修饰的名词关系比较复杂。例如:
boiling point=a temperature point at which something begins to boil 沸点
a walking tractor=a tractor which a driver can operate while he or she is walking behind it 手扶拖拉机
三、动名词的逻辑主语
  带有逻辑主语的动名词称为动名词的复合结构。当动名词的逻辑主语与句子的主语不一致时,要在动名词之前加上物主代词或名词所有格,这便构成了动名词的复合结构。其中物主
代词(名词所有格)是逻辑上的主语,动名词是逻辑上的谓语。动名词复合结构在句中可作主语、宾语、表语等,分别相当于一个主语从句、宾语从句、表语从句。如:
  Her coming to help encouraged all of us. 他来帮忙鼓舞了我们所有人。 (=That she came to help encouraged all of us.)
  Jane’s being careless caused so much trouble. 简的粗心惹来了不少麻烦。 (=That Jane was careless caused so much trouble.)
  在口语中,如果动名词复合结构作宾语,其中的物主代词常用人称代词宾格,名词所有格常用名词普通格来代替,但在句首作主语时不能这样来代替。如: