1、过去发生的两个动作，先发生的`用过去完成时
With their help I realized that I had been wrong.
2、过去某时以前发生的动作或情况
He hasn’t finished yet.
He didn’t finish yesterday evening.
He hadn’t finished by yesterday evening.
3、常用过去完成时的情况
①No sooner…than…. Hardly…when…
No sooner had he begun his speech than he was interrupted
②expect, hope, think, want, suppose等动词的过去完成时（或一般时）表示想做而未做的事
I had planned to send him a telegram, but I didn’t manage it.
4、使用过去完成时的必要性和非必要性
①句意十分清楚时，可用一般时
After I finished, I went home.
②常用一般过去时表示依次发生的动作
I got out of the taxi, paid the fare（车费) and managed it.
③有时必须明确，特别是含when时
When I arrived, Ann left.
(同时见到）（见到Ann)
When I arrived, Ann had left.
（先后发生）（没见到）
5、常用过去完成时的时间主状语
by the end of +过去时间 ； by + 过去时间
by the time + 过去时间；过去时间 + before
比较：
By the time he was 11, he had learned 3000 words .
By the time he is 11, he will have learned 3000 words.
By the time last week, I had learned 3000 words.
By the time next week, I will have learned 3000 words
