一日一句【2】过去完成进行时和过去完成时

过去完成进行时和过去完成时

示例：

The plane was delayed. When we arrived, Bill had been waiting for two hours.
飞机误点了。当我们到达时，比尔已经等了两个小时。

过去完成式表达的是比过去某一件事情或动作更早发生的事情或动作。过去完成进行时(had + been + -ing)用于叙述我们提到的一个过去时刻之前一直继续着的、历时较长的动作或情况。这一动作或情况一直延续到我们提到的那一个过去时刻。而这一动作或情况还有可能会延续下去。

He had been sitting there for thirty minutes when she finally appeared.
他坐在那儿等了半小时她才到来。

When her mother returned from USA, she had been studying in the University for two semesters.
当她母亲从美国回来时，她在这所大学里已读了两个学期。