过去完成时用于描述在过去某一时间点之前已经完成的动作或状态。以下是一些例句：
在晚饭前完成作业
I had finished my homework before supper.
在到达剧场前戏已经开始了
The play had already started when we got to the theatre.
在六月底之前已经治疗了一万多名患者
By the end of June, they had treated over 10,000 patients.
自1949年以来一直在那家工厂工作
He said he had worked in that factory since 1949.
在醒来之前
When I woke up, it had already stopped raining.
在到达电影院之前，电影已经开始了
We had already arrived at the cinema, but the movie had already started.
在通知我之前，我已经错过了这个机会
She had already informed me, but I had already missed the opportunity.
这些例句展示了过去完成时在描述过去事件顺序和完成状态方面的应用。希望这些例子对你有所帮助!
