过去完成时的结构：“助动词 had + 过去分词”，其中 had 通用于各种人称。
表示在过去某一时间或动作之前已经发生或完成了的动作，即“过去的过去（ past-in-the-past ）”。
表示某一动作或状态在过去某时之前已经开始，一直延续到这一过去时间，而且动作尚未结束，仍然有继续下去的可能。
例如：
By the end of last year, he had worked in the factory for twenty years.
到去年年底为止，他已经在这个工厂工作了20年。（ 到去年年底为止已工作了 20 年，还有继续进行下去的可能）
扩展资料
与过去完成时连用的时间状语有：
（1）by + 过去的时间点，例如：
I had finished reading the novel by nine o'clock last night.
到昨天晚上九点钟为止，我已经读完了这本小说。
（2）by the end of + 过去的时间点，例如：
We had learned over two thousand English words by the end of last term.
到上学期末为止，我们已经学了两千多单词。
（3）before + 过去的时间点，例如：
They had planted six hundred trees before last Wednesday.
在上周三之前，他们已经植了六百棵树。
过去完成时的结构是：
肯定句：主语+had+done+others
否定句：主语+had+not+done+others
疑问句：had+主语+done+others
肯定回答：YES,主语+had/否定回答：NO,主语+ hadn’t
特殊疑问句：特殊疑问词+had+主语+done+others
被动语态：主语+had（not）been+done+others
过去完成时：
过去完成时是把时间推移到过去某一时间之前，与现在不发生联系，由＂had + -ed分词＂构成。
举例：
肯定句：
I had arrived.
我已经到了。
否定句：
However,Her father had not brought her birthday presents.
然而，她的父亲没有给她买生日礼物。
疑问句：
Had Lisa gone to costume ball ?
丽莎已经去化妆舞会了吗？
Yes,she had.
是的，她去了。
No,she hadn’t.
没有，她没去。
特殊疑问句：
Why had The Castle become a memory of generation?
为什么电影城堡已经成为了一代的记忆？
被动语态：
At the end of last year,another magic design had been completed.
在去年低，另一个神奇的设计已经完成。
参考资料
沪江英语：https://www.hjenglish.com/shitai/p930260/
本回答被网友采纳1、概述
过去完成时表示过去某一时间或动作以前已经发生或完成了的动作。它表示动作发生的时间是“过去的过去”。表示过去某一时间可用by, before等构成的短语，也可用when, before等引导的从句或通过上下代表示。
His eyes shone brightly when he finally received the magazine he had long expected. 当她终于收到她盼望已久的杂志时，她兴奋得两眼闪光。
By the time he was twelve, Edison had begun to make a living by himself.12岁时，爱迪生就开始自己谋生。
2、构成
过去完成时由“助动词had+过去分词”构成。其否定式、肯定式、疑问式如下表：
肯定式 否定式 疑问式
I(we) I(We) you
You had read it. had not read it Had they read it?
He(She, They) He(She ,They) he
注意：had not 常简略为hadn't。
They asked me to have a drink with them and said it was at least ten years since I had enjoyed a good drink. 他们请我和他们一起喝酒，并说我自上次喝酒到现在至少十年了。
We had learnt 30 lessons by the end of last month.到上个月末为止，我们已经学了30课。
He said we hadn’t seen each other since I left Beijing.自从我离开北京，我们还没见过面。
3、过去完成时的用法
过去完成时的主要用法和现在完成时一样。不同的是，过去完成时把时间推移到了过去某一时间之前，与现在无关。
（1）过去完成时表示在过去某一时间或动作以前已经完成了的动作。这个过去的时间状语有by, before等介词短语或when, before等引导的从句。
Helen had left her keys in the office so she had to wait until her husband came home. 海伦把钥匙忘到办公室里了，因此她不得不等她丈夫回来。
When we got to the cinema, the film had already begun.当我们到达电影院时，电影已经开始了。
He told me that he had visited the Great Wall before.他告诉我他以前参观过长城。
By the end of the match, they had kicked 2 goals, and we had kicked 4.比赛结束时，他们踢进了2个球而我们踢进了4个球。
When Jack arrived he learned Mary had been away for almos t an hour.杰克到达后得知玛丽走了近一个小时了。
（2）表示动作在过去某一时间之前开始，一直延续到过去的这一时间，而且还可能继续下去的动作，常和for, since构成的短语或引导的从句连用。
The news came as no surprise to me. I had known for some time that the factory was going to shut down. 听到这个消息我并不感到吃惊。工厂要倒闭这件事我早就知道了。
By the time I left the school, he had taught the class for 3 years.到我毕业时，他已经教那个班三年了。
He said he had made great progress since he came here.他说自从他来这里他已经取得了很大进步。
（3）用于表示与过去事实相反的虚拟条件从句或as if从句中表示与过去事实相反
If he had seen you yesterday, he would have asked you about it.假如他昨天看到你，他就会问你这件事了。
I should have called you if I had known your telephone number.假如我过去知道你的电话号码，我就给你打电话了。
He described the scene as if he had been there.他描绘的景色如同他去过那里一样。
Had I known that you wanted the book, I would have sent it.如果我知道你要这本书，我会送来的。
（4）表示假设的宾语从句
放在像said，told，asked，thought，wondered等过去时动词的后面，表示在这些动作发生之前已经发生了的事情。
My friend told me that he had passed the exam.我的朋友告诉我，他已通过了考试。
He asked me whether I had seen the film the night before.他问我头一天晚上是否看过那部电影。
She wondered who had left the door open.她想知道谁敞着门的。
（5）用在 "It was the first/second/third…time that…”句型中
在此句型中，主句用了一般过去时，that引导的定语从句要用过去完成时。
This was the first time they had met in thirty-nine years. 这是39年里他们第一次见面。
It was the first time we had spoken together. 这是我们第一次在一起说话。
（6）intend, mean, hope, want, plan, suppose, expect, think等动词的过去完成时可以表示一个本来打算做而没有做的事
这种结构也可以表示过去未曾实现的设想、意图或希望等，含有某种惋惜。
I had intended to call on you yesterday, but I had an unexpected visitor.我本来昨天打算要去看你，但我来了个不速之客。
We had meant to tell her the news but found that she wasn’t in.我们本想把这个消息告诉她的，但发现她不在家。
（7）过去完成时常用结构有“hardly, scarcely, barely … when, no sooner… than等副词的句子里。
She hardly had gone to bed when the bell rang.他刚睡下铃就响了。
No sooner had they left the building than a bomb exploded.他们刚刚离开大楼，一颗炸弹就爆炸了。
（8）当before , after, as soon as 等引导的从句里的动作与主句的动作紧接时，由于这些连词本身已经说明了两个动作发生的先后关系，因此两个动作均可用一般过去时表示。
We had breakfast after we did morning exercises.做完早操之后，我们吃早饭。
The train started to move just before we reached the station.我们到车站时火车刚开动。
As soon as they got there, they started to study.他们一到那里就开始学习了
时间状语有：by the tine、by last year、by the time of 等