一日一句【79】before与现在完成时连用

before与现在完成时连用

示例：
Have you seen this movie before?
你以前看过这电影吗？

before可与现在完成时连用，表示“在现在以前的任何时候”(at any time before now)的意思。

She’s never worker as a waitress before, so she is very nervous.
她此前从未做过女侍应，因此她很紧张。

before也可表示“在过去某个时间之前”(before then)或“在我们讲到的过去某个时刻之前”(before the past time we are talking about)。这时before是和过去完成时连用：

She realized that she had seen him before.
她意识到她以前见过他。

如果比较具体地说“在过去某时间之前”，例如说three days before, a year before, a long time before等时，动词也是用过去完成时。

When I went back to the school that I had left eight years before, everything was different.
当我回到阔别了八年的学校时，发现一切都变了。