过去完成时的标志词有by、by the time 过去完成时还可用在hardly…when…, no sooner…than…, It was the first (second, etc) time (that)…等固定句型中。
过去完成时的结构(1)肯定句：主语+had+动词过去分词+其他.
(2)否定句：主语+had+not+动词过去分词+其他.
(3)疑问句：Had+主语+动词过去分词+其他?
肯定回答：Yes,主语+had.否定回答：No,主语+hadn't.
(4)特殊疑问句：特殊疑问词或词组+had+主语+过去分词+其他?
(5)被动语态：主语+had(not) +been+动词过去分词+其他.
过去完成时的句子(1)I had been at the bus stop for 20 minutes when a bus finallycame.当车来的时候，我在车站已等了20分钟。
(2)He said he had worked in that factory since 1949.他说自从1949年以来他就在那家工厂工作。
(3)I didn’t know a thing about the verbs, for I had not studied mylesson.我对动词一无所知，因为我没有好好学习功课。
(4)She found the key that she had lost.她丢失的钥匙找到了。
(5)When I woke up, it had already stopped raining.我醒来时雨已停了。
(6)It had rained heavily last month. 上个月雨下得很大。
(7)A thief had stolen my watch. 小偷偷走了我的手表。
(8)They had visited a doctor. 他们已经看过医生了。
(9)I had been to America. 我曾去过美国。
(10)The students had gone before the teacher came.老师进来以前学生们已经走了。
