past perfect tense构成：助动词had + 动词的过去分词 用法 ： 1. 过去完成时动词表示过去某一时间或某 一动作之前完成的动作或状态。强调过去 某一动作发生在另一动作之前时。 1.他说他以前见过你。 He said that he _ (see) you before. had seen 2. 到六点钟为止他们已经工作八小时了。 By six oclock they _(work) for eight hours. had worked2. 过去完成时词可以表示过去某一时 刻之前发生的动作或呈现的状态，这 一动作一直持续 或将继续下去。 By six oclock they _ (work)for eight hours. When I came to GZ , he _(be) there for a long time. 用法： 1. 到了六点钟为止，他们已经工作了八小时了。 2. 我到广州时，他在那里很长时间了。 had worked had been 3.到上个月中旬我们在北京住了有五年时间了 。 By the middle of last month w
