Section Ⅲ　Grammar--过去完成时

语 境 自 主 领 悟 先观察原句 后自主感悟 ①By the 1920s，he had become an explorer，searching for the tombs of the Egyptian kings.

②I returned the book that I had borrowed.

③Upon their entering the tomb，Cater's lucky pet bird，which he had left in Cairo，was swallowed by a snake.

④Then，a few months after Carter had opened the tomb，Lord Carnarvon，who was also present when the tomb was opened，fell ill with a fever and died in Egypt.

⑤He said he had worked in that factory since 1949.

⑥I had been at school for half an hour when Li Lei came. 1.过去完成时的构成：had＋过去分词。

2.过去完成时表示在过去某一时刻或动作以前已经完成了的动作，即"过去的过去"如句①②③④。

3.过去完成时可以指过去的动作延续到过去的某个时刻，如句⑤⑥。 　　

　　一、过去完成时的构成

　　过去完成时由"had＋过去分词"构成。

　　二、过去完成时的用法

　　1．过去某一时刻或动作之前已完成的动作或存在的状态。可以用by，before等介词短语或一个时间状语从句来表示，也可以用一个表示过去的动作来表示，还可通过上下文来表示。

When the explorer hurried to the destination，the others had already left.当这名探险者匆忙赶到目的地的时候，其他人已经离开了。