过去完成时
1. 表示在过去某一时刻以前已经开始并一直延续到这一时刻、或是在此刻前已经完成的动作。
[例句] By the end of last term, we had learned 1,000 English words.
2. 有些动词 (如： hope, think, expect, mean, intend, suppose, want等) 的过去完成时可表示过去未曾实现的希望、打算或意图。
[例句] I had hoped to see more of Beijing.