had done是什么時(shí)態(tài)怎么翻譯

　　用法：

　　1、表示某一動(dòng)作在過去某一時(shí)刻之前已完成。例如:

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

　　昨夜十點(diǎn)鐘之前他已上床去睡了。

　　2、與一般過去時(shí)搭配，表達(dá)某一動(dòng)作在過去的動(dòng)作發(fā)生時(shí)已完成。例如：

　　The train had started when I got to the station.

　　當(dāng)我到達(dá)車站時(shí)火車已開走了。