考生們在復習考研英語的時候總是會跟語法打交道，那么考研英語語法中的過去完成時又是怎么樣的呢?下面就跟著小編一起去看看吧!
一律用had + 過去分詞構成。
用法：
1)表示發生在過去某一時間或動作之前的事情，即“過去的過去”。用過去完成時，必須有一個過去的時間或動作來作參照，說明在此之前某事已發生。如果兩個動作都是在過去發生的，先發生的用過去完成時，后發生的用一般過去時。例如：
She told me she had been there three times before. 她告訴我她以前到過那里三次。(“去過”發生在“告訴”之前)
How long had he taught here by the end of last term? 到上學期末為止，他在這里教學多長時間啦? (“教學”發生在上學期末結束之前)
When we arrived, the football match had already begun. 我們到的時候，足球賽已經開始了。
She had visited China twice before she came this year. 她今年來中國之前已訪問過中國兩次了。
2)過去完成時動詞可以表示過去某一時刻之前發生的動作或呈現的狀態，這一動作一直持續到過去這一時刻或將繼續下去。例如：
By the middle of last month, I had lived in Beijing for five years. 到上月中旬，我已在北京住了五年了。
By six o’clock they had worked for eight hours. 到六點為止，他們已工作八小時了。
When I came to Shanghai, he had been there for a long time. 我到上海時，他在那里很長時間了。
3)過去完成時動詞常用于間接引語和虛擬語氣，我們以后會詳細講述。
4)此外，過去完成時常用于 no sooner…than… 和 hardly(scarcely) …when… 這兩個句型，前面部分用過去完成時，后面部分用一般過去時。例如：
No sooner had he stolen the purse than he was caught red-handed. = He had no sooner stolen the purse than he was caught red-handed. 他剛偷到錢包就被當場抓獲。
Saddam had hardly realized what was happening when he was captured. = Hardly had Saddam realized what was happening when he was captured. 薩達姆還沒有意識到在發生什么事情就被抓獲了。