过去完成时：表示发生在过去的两个动作在前的那一个，它表示句子中描述的动作发生在“过去的过去”。
基本形式：过去完成时由had+过去分词构成，因此无人称变化
一定式：I had/I'd worked等
否定式：I had not/hadn't worked等
疑问式：had I worked等
否定疑问式：had I not/hadn't I worked等
时态使用方法：
1. 过去完成时是与目前完成时相当的过去式：
目前完成时：Ann has just left.If you hurry you’ll catch her.
过去完成时：When I arrived Ann had just left.
但，过去完成时不像目前完成时那样限于表达未指明时间的动作，因此可以说：He had left his case on the 4∶40 train.
2.目前完成时可以和 since/for/always等词连用，表示一个开始于过去并仍在继续或刚刚结束的动：
与此同理，过去完成时也可以用来表示在所说的过去某一时刻之前就已开始的动作。
1)在该时刻仍然在继续。
比如：Bill was in uniform when I met him.He had been a soldier for ten years.
2)在该时刻停止或刚刚停止。
比如：The old oak tree, which had stood in the churchyard for 300 years, suddenly crashed to the ground.
但应注意，过去完成时还可以用来表示：
3)在所说时刻之前某一时候停止的动作。
比如：He had served in the army for ten years; then he retired and married.
3. 过去完成时也是一般过去时的过去时，用来表示叙述者或主语在过去的某一时刻回顾更早的动作：
比如：He met her in Paris in 1977.He had last seen her ten years before.Herhair had been grey then; now it was white.
更多精彩内容 新东方网英语频道
全国新东方英语课程搜索
（编辑：王美娇）
