英语语法过去完成时的被动语态的知识点
英语语法过去完成时的被动语态的知识点
过去完成时的被动语态是英语语法中的一个重要知识点，它结合了过去完成时态和被动语态的特点，用于表示在过去某一时间之前已经完成的动作。本文将详细介绍过去完成时被动语态的概念、构成形式、用法以及与现在完成时被动语态的区别，并通过多个例句帮助读者更好地理解这一语法点。
过去完成时的被动语态的概念
过去完成时的被动语态是过去完成时态和被动语态的叠合。表示过去某一时间以前已经完成的动作，常与by，before等引导的时间状语连用。由“had+been+过去分词”构成。
过去完成时的被动语态的肯定式为：had + been + done。
如：The task had been finished before 12:00 yesterday.过去完成时的被动语态的否定式为：have / has + not + been + done。
如：The task hadn't been finished before 12:00 yesterday.过去完成时的被动语态的一般疑问句需将had提到主语的前面。
如：Had the task been finished before 12:00 yesterday?过去完成时的被动语态的特殊疑问句为：疑问词 + had+ been + done。
如：What time had the task been finished yesterday?
过去完成时被动语态的用法
过去完成时由“had+过去分词”构成，表示在过去某一时刻或某一动作之前发生的动作或状态，句中常用by，before，until，when等词引导时间状语。
如：We had built five new buildings by the end of last year. 过去完成时的被动语态有以下三种形式：
- 肯定结构：主语＋had been done＋其他成分
- 否定结构：主语＋had not been done＋其他成分
- 疑问句结构：had＋主语＋been done＋其他成分；
疑问词＋had＋主语＋been done＋其他成分
过去完成时的被动语态常用于以下情况
- 表示过去某一时间以前已经完成的动作，常与by, before等引导的时间状语连用。
如：
- By the time he got to the school, the first period had been finished.
- The classroom hadn't been cleaned before the teacher came.
- How many buildings had been destroyed when the hurricane ended?
- Had the new plan been discussed before the meeting?
- 在told, said, knew, heard, thought等动词之后的宾语从句中，若表示过去某一被动动作时，用过去完成时。
如：
- The said the production costs had been reduced.
- The boy was reminded that his homework had not been handed in.
- The media reported more than 1,000 people had been killed in the earthquake.
- 根据语意可以判断出动作先后的被动语态，用过去完成时。
如：
- As the assignment had been done, he went on to search the Internet.
- He did what he had been told to.
另：当从句由after，before，when或assoonas引导时，主句和从句都可以用一般过去时。
如：
- When he arrived, he called her.
- They locked the door before they left.
过去完成时与现在完成时被动语态用法区别
现在完成时被动语态表示相对于现在来说已被完成的动作，过去完成时被动语态表示相对于过去某一时刻来说已被完成的动作。
例如：
This polluted river has been cleaned. 这条被污染了的河流已被净化。
析：该句表示到现在为止这条河流已被净化。He said this book had been translated into Japanese. 他说这本书已被译成日语。
析：该句表示到他说话时所体现的时间为止这本书已被译成日语。