过去完成时 过去完成时的动作须在过去某一时间之前发生，即发生在“过去的过去”。 1．过去完成时的构成 过去完成时是由“had+过去分词”构成的。
Soon I realized I had made a serious mistake. 我很快就意识到我犯了一个严重的错误。
Had he gone home when you arrived?
你到的时候他已经回家了吗？
2．过去完成时的用法 ①“已完成”用法
表示某一动作或状态在过去某一时间之前或过去某一动作之前已经完成。句中常用by引导的时间状语或以 before, until, when, than等词引导的内含一般过去时的时间状语从句。
By 5:00 yesterday morning we had
done that work. 到昨天早上5点钟时，我们已经做完了那件工作。
I had learnt 5000 words before I entered the university. 我在进大学之前就已学了5000个单词。
It rained yesterday after it had been dry for many months. 旱了好几个月之后，昨天
下雨了。
②“未完成”用法
表示一个动作或状态在过去某一时刻之前就已开始，一直持续到这一过去时间，还可能再持续下去。 John and Jane had known each other for a long time before their marriage. 约翰和简在结婚前就认识很长时间了。
She said she had
made much progress since she came here. 她说自从她到这儿后已取得了很大的进步。 ③“想象性”用法
过去完成时有时表示一种未实现的愿望或想法，主要用在if引导的和过去事实相反的条件句以及wish, as if引导的从句中。
If she had worked hard, she would
have succeeded. 要是她努力的话，她就会成功了。（事实上她没努力，也没成功。）
I wish I had gone with you to the concert. 我要是和你一起去音乐会就好了。
The two strangers talked as if they had been good friends for many years. 那两个陌生人交谈起来
就像是多年的老朋友。 ④表示“刚刚……就……”
过去完成时常用在hardly/scarcely/barely ... when..., no sooner ... than ... 等结构中，表示“刚刚……就……”。
Hardly had he begun to speak when the audience interrupted him. 他刚开始演讲，听众就打
断了他。
No sooner had he arrived than he went away again. 他刚到就又走了。 提示：
intend, mean, hope, want, plan, suppose, expect, think等动词的过去完成时可以用来表示一个本来打算做而未做的事。
I had meant to come, but
something happened. 我原本打算来的，但有事发生了。
I had intended to call on you, but was prevented from doing so. 我本打算去看你的，但没能去成。
3．过去完成时与一般过去时的比较
一般过去时表示过去时间的动作或状态。过去完
成时表示的动作或状态发生在一般过去时表示的动作或状态之前，因此它表示的是“比过去更过去 