不久以前这里发生过一件事，我直到好多天以后才知道，但现在我要把这件事告诉你。

Now, something had been happening there a little before, which I did not know anything about until a good many days afterwards, but I will tell you about it now.

youdao

这不是以前没有发生过的。

It's not like this hasn't happened before.

youdao

我们提出了一开始看起来很有吸引力的理论，但是接下来，你要如何解释以前也发生过这种情况呢？

We have what at first seems like a pretty attractive theory, but then, how do you explain the fact that this has happened before?

youdao

This had never happened in an English class before.

这种情况在以前的英语课上从来就没发生过！

耶鲁公开课 - 文学理论导论课程节选