1 、過(guò)去完成時(shí)是一個(gè)相對(duì)時(shí)態(tài)，表示過(guò)去的過(guò)去，只有在兩個(gè)過(guò)去發(fā)生的動(dòng)作相比較時(shí)才可顯示出來(lái)。
As soon as we got to the station, the train had left.
注：主從句表達(dá)的動(dòng)作緊接時(shí)，即兩動(dòng)作發(fā)生的時(shí)間沒(méi)有明顯時(shí)間上的懸殊或空檔時(shí)，主從句都可用一般過(guò)去時(shí)。
e.g. Where did your brother study before he joined the army?
2 、過(guò)去完成時(shí)可表示截止過(guò)去某一時(shí)間動(dòng)作的總或動(dòng)作的結(jié)束。
By the end of last month. We had reviewed four books
By eight o`clock, he had finished his homework.
與這個(gè)時(shí)態(tài)連用的時(shí)間狀語(yǔ)常有：
by 1985, by eight o`clock, by then, by the end of last month, by the time when, when, as soon as, before 等連詞引導(dǎo)的時(shí)間狀語(yǔ)從句，表示主句動(dòng)作結(jié)束的時(shí)間。
As soon as we got to the station, the train had left.
注：主從句表達(dá)的動(dòng)作緊接時(shí)，即兩動(dòng)作發(fā)生的時(shí)間沒(méi)有明顯時(shí)間上的懸殊或空檔時(shí)，主從句都可用一般過(guò)去時(shí)。
e.g. Where did your brother study before he joined the army?
2 、過(guò)去完成時(shí)可表示截止過(guò)去某一時(shí)間動(dòng)作的總或動(dòng)作的結(jié)束。
By the end of last month. We had reviewed four books
By eight o`clock, he had finished his homework.
與這個(gè)時(shí)態(tài)連用的時(shí)間狀語(yǔ)常有：
by 1985, by eight o`clock, by then, by the end of last month, by the time when, when, as soon as, before 等連詞引導(dǎo)的時(shí)間狀語(yǔ)從句，表示主句動(dòng)作結(jié)束的時(shí)間。