When I turned off the lights in the office, I locked the door and left.
以下几种表达都是正确的
【1】When I had turned off the lights in the office, I locked the door and left.
【2】After I had turned off the lights in the office, I locked the door and left.
【3】After I turned off the lights in the office, I locked the door and left.
【4】After turning off the lights in the office, I locked the door and left.
【5】Having turned off the lights in the office, I locked the door and left.
备注(1):第1/2/3为从属连词引导时间状语从句作主句时间状语。第4为介词短语作时间状语, 第5为现在分词完成体作时间状语。
备注(2):第1/2种表达等于第5种表达。第3种表达等于第4种表达。