過去完成時(shí)的概念：
過去完成時(shí)既可表示過去某個(gè)時(shí)間或動(dòng)作之前所發(fā)生的事情，也可表示過去某個(gè)時(shí)間或動(dòng)作之 前所發(fā)生的動(dòng)作一直持續(xù)到過去某個(gè)時(shí)間。過去完成時(shí)由“had+過去分詞”構(gòu)成。
如：She had leant 2000 English words by the end of last month.
過去完成時(shí)的應(yīng)用：
�。�1）與過去完成時(shí)連用的時(shí)間狀語(yǔ)可以多種多樣，使用它的主要依據(jù)是看其是否發(fā)生在“過去的過去”。
如：He had learnt some English before I went here. 在來這兒之前我學(xué)過一些英語(yǔ)。
He had written three stories by last year.到去年他已經(jīng)寫了三篇故事。
We had cleaned the room when he got there. 當(dāng)他到那兒時(shí)，我們已經(jīng)把房子弄干凈了。
He went there after he had finished his work. 他把事做完之后，就去哪兒了。
注意：當(dāng)主句跟由before, after, as soon as所引導(dǎo)的時(shí)間從句的動(dòng)作連接很緊密時(shí)，從句也可用一般過去時(shí)。
如：He went there after he read the letter. 他看了那封信后就去那兒了。
�。�2）過去完成時(shí)還經(jīng)常用于主句為過去時(shí)的賓語(yǔ)從句中。
如：He said he had been a soldier. 他說他當(dāng)過兵。
They said they had seen the film. 他們說這幕電影他們看過。
（3）在hardly/scarcely…when…,nosooner…than…兩個(gè)結(jié)構(gòu)中的主句通常要用過去完成時(shí)。
如：Hardly had I told her the news when she began to cry out. 她一聽到這一消息就大哭了起來。
Scarcely had he finished his supper when he went out. 他已吃完晚飯就出去了。
No sooner had he fallen asleep than he lay down on the bed. 他一躺倒床上就睡著了。
�。�4）動(dòng)詞expect, hope, suppose, think, want等的過去完成時(shí)可用來表示未實(shí)現(xiàn)的計(jì)劃、打算或希望。
如：I had hoped to see you. 我本希望來看你。
He had wanted to buy a house in Beijing. 他本想在北京買棟房子。
過去完成時(shí)與一般過去時(shí)：
�。�1）過去完成時(shí)表示以過去某時(shí)間為起點(diǎn)以前所發(fā)生的動(dòng)作或存在的狀態(tài)，即：過去完成時(shí)強(qiáng)調(diào)“過去的過去”，而一般過去時(shí)只表示以現(xiàn)在時(shí)間為起點(diǎn)以前所發(fā)生的事情或存在的狀態(tài)。
如：He studied there two years ago. 他在那兒學(xué)習(xí)了兩年。(離現(xiàn)在兩年)
He said he had studied there two years ago. 他說他在那兒學(xué)習(xí)了兩年。(離他說話時(shí)兩年)
�。�2）表示過去某個(gè)時(shí)間以前所連續(xù)發(fā)生的兩個(gè)或兩個(gè)以上的動(dòng)作時(shí)，一般用and, then, but按照動(dòng)作的先后順序連接，此時(shí)通常用一般過去時(shí)而不用過去完成時(shí)。
如：He said he went the shop and bought some food. 他說他去商店買了一些食品。
（3）兩個(gè)動(dòng)作相繼發(fā)生，可用一般過去時(shí)；如第一個(gè)動(dòng)作需要若干時(shí)間完成，用過去完成時(shí)。
如：When I heard the news, I was very excited.
�。�4）敘述歷史事實(shí)，可不用過去完成時(shí)，而只用一般過去時(shí)。
如：Our teacher told us that Columbus discovered America in1492.