过去完成时

She had left before I arrived.

我到达之前她已经离开了。

By the time we arrived, the movie had already started.

我们到的时候，电影已经开始了。

I had never seen such a beautiful sunset before that day.

在那之前我从没见过这么美的日落。

She had finished the report before the deadline.

她在截止日期前完成了报告。

Had they known the truth, they would have acted differently.

如果他们知道真相，他们会采取不同的行动。

The rain had stopped by the time we left.

我们离开时雨已经停了。