1 第六讲：动名词和分词与动词不定式用法比较 英语中的不定式、动名词和分词（现在分词和过去分词）在句中不能充当谓语，故被称为非谓语动词。它们都有否定式、被动式和完成式。否定词not, never 总放在它们之前，被动式及完成式见下表： 不定式 动名词 分词 主动 被动 主动 被动 主动 被动 一般式 to keep to be kept keeping being kept keeping being kept 现在式 to have kept to have being kept having kept having been kept having kept having been kept 完成式 to have keeping \ \ \ \ \ 完成进行式 to have been keeping \ \ \ \ \ 其中，动名词还可以被代词及名词所有格修饰，构成动名词的复合结构。这种代词和名词所有格充当动名词的逻辑主语。 -------His anxiety doesn't justify his being so rude to his mother. 他的焦虑不是他对母亲这么粗鲁的理由。 -------The father was angry at his son's spending money like water. 父亲对儿子的花钱如流水感到愤怒。 在口语或非正式语体中，也可用宾格代替代词和名词的所有格。故上面两句可改为： -------His anxiety doesn't justify him being so rude to his mother. -------The father was angry at his son spending money like water. 1.作主语 (1)动名词和不定式都可充当主语，意义上一般区别不大。 -------Seeing is believing. 和 To see is to believe. 都意为：百闻不如一见。 但动名词常表抽象性概念，泛指习惯性动作或抽象概念，而不定式指某一具体时间内或将来时间中的具体的、特定的动作。 2 -------Swimming does good to our health, but to swim on such a cold day is unthinkable. 游泳对我们的健康有好处，但在这么冷的天气里去游泳是难以想象的。 (2)不定式通常用 It 作形式主语，而动名词通常直接放在句首作主语。 -------It's necessary to take more sports and games. 多进行体育运动是必要的。 -------It's nice to talk to such an interesting person as you.和你这么有趣的人谈话很有意思。 Climbing mountains is tiring. 爬山是很累人的。 (3)动名词用 It 作形式主语时常用于一些固定结构中，如 -------It's no use (good, sense, useless, pointless, a ...
