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)

1.构成: have / has been doing

3.现在完成时与一般过去时的区别:

①.现在完成时和一般过去时所表示的动作都发生在过去, 但前者将过去的动作与现在的结果或对现在的影响联系起来, 而后者只限于表示过去的动作本身, 与现在无关

②.现在完成时不能与表明确时间的状语如: yesterday, last year, two days ago, when I came in等连用, 但可与表示不明确时间的状语如: already, yet, sometimes, often, before, lately, recently, once, twice, ever等连用, 也可以和包括现在在内的时间状语如: this morning, today, this week, this year等连用

　　　　 a. She has already come.

　　　　 b. I have met him before.

　　　　 c. Ma Hong has always been a good student.

　　　　 d. Have you ever been to the Great Wall ?

　　　　 e. I have seen him this morning.