3.现在完成(进行)时表示将来

现在完成(进行)时可用在时间和条件状语从句中，表示将来完成的动作。(参见状语从句)

I shall go as soon as I have finished my lessons．

我一做完功课就去。

If you have finished the book before I leave，please give it back to me．

如果在我离开前你看完了这本书的话，请还给我。

When you have finished your supper，change clothes for the evening party．

吃完晚饭后，请换掉衣服准备参加晚会。

When you have learned English，you will find it a bridge to so much knowledge．

当你学会了英语后，你会觉得它是通向丰富知识的桥梁。

You can enter yourself for the exam，if you have learned 2，000 words．

如果你学了2 000个单词的话，你就可以报名参加考试。

提示：

有时状语从句中的现在完成时有时并不是表示将来，而是表示习惯。

When I have had a bad day at school，I read Keats and forget everything．(人教大纲版高一下第31页)

如果哪天上学不开心，我就朗诵起济慈的诗，这样就会忘却一切烦恼。When I have studied a book，I write a report on it．

我研读完一本书后就写一篇读书报告。

现在完成时强调对现在的影响，因此将它用于because状语从句就是顺理成章的事了。

You all knowhow to write a story，because we have read and written many stories in class．(人教大纲版高一下第20页)

你们都知道应该怎么写故事，因为我们在课堂上阅读、写作了许多故事。