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。
The man sitting beside me on the plane was very nervous. He had not flown before.
飞机上坐在我旁边的人很紧张，他以前从没乘过飞机。
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。
He had just finished sweeping the classroom when the teacher returned from the office.
老师从办公室回来时，他刚把教室打扫完。
They came earlier than we had expected.
他们到得比我们预料的要早。
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。
注意：
在包含before和after的复合句中，因为从句动作和主句动作发生的先后顺序已经非常明确，可以用一般过去时代替过去完成时。
The train (had) started before I reached the station.
在我到达车站之前，列车已经开了。
After he (had) arrived in England, Marx worked hard to improve his English.
马克思到达英格兰之后，努力提高他的英语水平。
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。
Up to that time all had gone well.
直到那时一切都很顺利。
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