1.构成: had been doing

2.用法:

①.表示过去某时间或动作以前己经完成的动作或己存在的状态, 即“过去的过去”

　　　 　a. When all his money had gone, Marx had to leave his house in London.

　　　 　b. Marx had learned some English before he got to England.

　　　 　c. He said he had never been to Shanghai.

　　　 　d. By the middle of last month I had lived in Beijing for five years.

②.在带有after / before引导的时间状语的句子中, 由于after / before本身的词义己经表明了时间的先后, 所以这类句子中常用一般过去时代替过去完成时

　　　 　a. We left the house before it began to rain.

　　　 　b. I didn’t wait long before he came.

　　　 　c. After we finished the tea, we all sat on the grass.

　　　 　d. After he arrived in England, Marx worked hard to improve his English.

1.构成: had done

2.用法:

①.表示过去某一时刻正在进行或一段时间内一直在进行的动作或情况

　　　　 a. This time yesterday we were having an important meeting.

　 　　　b. A year ago we were living in Shanghai.

　 　②.过去进行时常与always, continually, frequently等词连用, 表示过去经常发生或反复发生的情况

　　　　 a. The old man was always losing his way.

　　　　 b. The two brothers were frequently quarrelling.

③.表示过去将要发生的动作, 这一用法仅限于一些表示位置转移的动词, 如: go, come, start, stay, leave等

④.过去进行时经常与一般过去时配合使用, 过去进行时表示过去的时间背景

　　　　 a. The teacher was giving us a lesson when Tom walked into the room.

1.构成: was / were doing

2.用法:

①.表示过去某一时刻或某一段时间内发生的动作或情况, 其中包括习惯性动作

　　　　 a. I met him yesterday.

　　　　 b. I used to go to school early every morning.

　　　　 c. He entered the classroom, sat down at his desk and began to work.

　　　　 d. Last night, I listened to the radio for two hours and went to bed at midnight.

②.在时间, 条件状语从句中用一般过去时代替过去将来时

　　　　 a. Helen had left her keys in the office so she had to wait until her husband came home.

　　 ③.用一般过去时的句子一般有过去的时间状语, 有时也用地点状语暗示动作的发生是在过去

　　　　 a. Have you seen a pen ? I left it here this morning.

1.构成: 用动词的过去式表示

4.现在完成时与现在完成进行时的区别: 前者着重表示过去动作对现在的影响或结果; 后者着重表示过去动作的持续进行

　　　　 a. I have written six letters since I got back.我己经写了六封信 (强调结果)

　　　　 b. I have been writing letter since I got back. 我回家后一直在写信 (强调“一直在写”)

　　　　 c. I have read this book.我读过这本书了(强调“读过”这一结果)

　 　　　　d. I have been reading this book.我一直在读这本书 (强调“一直在读”)

3.用法:

①.表示现在之前的一段时间里一直进行的动作, 此动可能仍在进行, 也可能刚刚停止

　　　　 a. I have been reading the book all the morning.

　　　　 b. He has been staying here for two hours.

　　　　 c. I have been living in Beijing since 1972.

②.表示现在之前的一段时间里一再重复的动作

　　　　 a. I have been calling you several times in the past two days.

2.特征: 现在完成进行时兼有现在完成时和现在进行时两者的特点

①.它具有现在完成时的特点, 即表示动作发生在过去, 延续到现在或对现在产生影响

②.它具有现在进行时的特点, 即可以表示此动作仍在进行或还会继续

　　　 　a. Mr. Smith has taught English for twenty years. ( 至今为止教过二十年英语, 至于teach是否结束或是否延续, 不得而知)

　　　 　b. Mr. Smith has been teaching English for twenty years.( 现在仍在教英语,而且将持续下去)