had done是什麼時態怎麼翻譯

用法：

1、表示某一動作在過去某一時刻之前已完成。例如:

He had gone to bed by 10:00 last night.

昨夜十點鐘之前他已上牀去睡了。

2、與一般過去時搭配，表達某一動作在過去的動作發生時已完成。例如：

The train had started when I got to the station.

當我到達車站時火車已開走了。