老师们好，
请问这句话能否和下面这句划等号？
Before I went to the police station, I called the clients office.
=When I went to the police station, I had called the clients office.
第一句非常不错，没任何问题。
第二句不能。尽管你想从时态上体现先后，但不符合逻辑：
一个人先后做了两个动作，让when 从句晚，主句早——讲不通。由于：when 的主句，总是指突发的，没办法预料的，没事先安排的。而你的主句则是安排的动作，已经发生。所以不符合逻辑。
When I arrived at the police station, I had called the clients office.（误。把when 改为before 才对，说明主句是事先安排的动作）
When I arrived at the police station, I called the clients office.（正。先到达后打电话）
从句晚，主句早，由于主、从句的两个主语不同，说明主句动作是在你不知情的状况下发生的。比如：
When I arrived at the station, the train had left.（正。火车先离开，我后到达）
