过去完成时的构成

来源：百度知道编辑：UC知道时间：2024/05/17 03:16:04

过去完成时是由“had +动词的过去分词”构成，
但是为什么说had通常用于任何人称？
had到底怎么变化？

意思即是任何人称做主语都是跟had, had 没有变化.
如:
The train had left when he reached to the station.
I had finished my homework by the time you called me.

Had是表过去时,当然就没有人称的变化啦!