语法图解
探究发现
①A Roman writer called Pliny wrote about a terrible volcanic eruption that he had witnessed as a young man.
②By 1748, they had found an awesome historical site.
③He had worked in the factory for five years before we moved here.
④The film had begun when they arrived at the cinema.
⑤I had hoped to meet you at the airport, but I was caught in a traffic jam.
⑥That dinner was the most expensive meal we had ever had.
⑦There was a knock at the door.It was the second time someone had interrupted me that evening.
⑧I had meant to come, but it occurred to me that I had some work to do.
[我的发现]
(1)过去完成时与特定的时间状语连用，如句②。
(2)句①③④中过去完成时用于主从复合句，主从句动作都发生于过去，且有先后关系。
(3)句⑥、句⑦中过去完成时用于拥有序数词或最高级的句型。
(4)过去完成时表示一种未实现的愿望或想法，如句⑤、句⑧。
