现在分词的时态

过去分词没有时态形式的变化，所以这里只讲现在分词的时态形式。

1)现在分词的时态形式

一般式writing

完成式having written

2)现在分词一般式其所表示的动作与谓语动词所表示的动作同时发生，或在谓语动词所表示的动作之前或后发生。如：

Working together with Dr. Bethune，we learnt a lot from him.

我们在和白求恩大夫一起工作期间，向他学到很多东西。

(working与leamt同时发生)

Knowing that they were going abroad next week ，they began to make preparations.他们知道他们下星期要出国，所以都开始作准备。(knowing发生在began之前)

He came up to me，saying"Glad to see you again."他来到我跟前说道，"很高兴又见到你。"(saying发生在came之后)

3)现在分词完成式其所表示的动作发生在谓语动词所表示的动作之前，常常用作状语，表示时间或原因。如：

Having done his homework，the schoolboy began to write his diary.这个小学生做完作业后，开始写日记。(having done his homework发生在began之前，表示时间。)

Not haying done it right, I tried again.没有做对，我就又试。

(not having done发生在 tried之前，表示原因。)