过去完成时 Past Perfect

表示在过去某一时间或某一动作之前就已经完成的动作（俗称“过去的过去”）。

• 结构公式：主语 + had + done (过去分词)
• 否定式：主语 + had not (hadn't) + done
• 疑问式：Had + 主语 + done...?
• I had done my homework by the end of last week. —— 上周末前我已经做好了家庭作业。
• When I arrived at the station, the train had already left. —— 当我到达车站时，火车已经开走了。
• She said that she had seen the film before. —— 她说她以前看过这部电影。

正在加载互动版…（需开启 JavaScript）