郭老师讲语法：过去完成进行时had been doing

       1、现在完成时表示的是开始于过去的动作一直持续到目前为止；同理，过去完成时则表示开始于过去某一时刻的动作持续到过去另一时刻为止，即动作开始时间应是“过去的过去”，动作结束时间是“过去”。所以，过去完成时可以说是个相对的时态，它不能离开过去时间而独立存在，它应是用在“过去时问”背景之下的时态。例如：

       By the end of last year, I had learned more than 2, 000 words. 到去年年底，我已经学了超过2000个单词.

       I had learned some English before I came to America. 在来美国前，我已学了一些英语。

       2、与过去完成时一样，过去完成进行时也必须以一个过去时间为前提，它表示在过去某一时间前一直在进行的动作，动作可能还将延续下去。例如：

       When she arrived, I had been waiting for three hours. 当她到时，我已经等三个小时了。

       I had been talking with her for quite a while before I realized who she was. 在意识到她是谁之前，我和她聊了很久。

       I had been looking for jobs for nearly a month before I finally got a position in this company. 在这家公司上班前，我已经找了将近一个月的工作。

【具体解析】

       1、过去完成进行时用于强调某动作在过去更早的某一段时间内一直在进行，并对过去

某一时刻产生结果。与它经常连用的表示时间的词有before, for, since, all day等。例如：

       She was very tired. She had been typing letters all day. 她很累了。她整天都在打信件。

       —Did you race horses before you got married? 你结婚前赛马吗?

       —Oh, yes! I’d been racing horses for years before I met my wife. 是的！认识我妻子之前我己经赛了好几年的马了。

       2、过去完成进行时可用来表示过去经常重复的动作。例如：

       Jill was angry. Jim had been phoning her every night for a whole week. 吉尔生气了。整整一星期，吉姆天天晚上都给她打电话。

       3、它还可以表示根据直接或间接的证据而得出结论。例如：

        Her eyes were red. It was obvious she had been crying. 她的眼睛红了。显然她刚哭过。

       4、在包含间接引语的句子中，如果引述词是过去时态，则现在完成进行时要改为过去完成进行时。例如：

      —What was Tom’s excuse for being late last night? 汤姆说他昨晚迟到的理由是什么?

       —He said he’d been making phone calls. 他说他一直在打电话。

【辨析】过去完成时与过去完成进行时的区别

       1、过去完成时与过去完成进行时有时可以替换使用。例如：Dan had worked / had been working for the firm for fifteen years when I first met him. 我第一次遇见丹时，他己在该公司干了15年了。

       2、过去完成时多用来强调结果，当需要表示某个工作己经完成时，只能用过去完成时。过去完成进行时，则更多强调动作本身过程。例如：

       When I got home, I found that Jill had been painting her room. 我回到家时，看见吉尔在粉刷她的房间。(工作尚未完成)

       When I got home, I found that Jill had painted her room. 我回到家时，发现吉尔己经粉刷过她的房间了。(己完成)

       When I arrived, they’d already put the fire out. 我到达时，他们己经把火扑灭了。(不可用过去完成进行时)      

【相关练习】

       1. It ________ for four days when we arrived, so the roads were very muddy.

              A. was raining          B. would be raining   C. had been raining    D. has rained

       2. He told us that he ________ there since 1982.

              A. has been living      B. had been living      C. would have lived   D. was living

       3. He had been learning English for 3 years before he came here and ________ now.

              A. is still learning                                      B. had been learning

              C. was still learning                                  D. has been learning

       4. By the end of last week, he ________ in the company for 10 years.

              A. had worked                                         B. had been working

              C. will have worked                                  D. would have worked

       5. Not until then did people know that he ________ important military information to the  enemy for a long time.

              A. sold                      B. would sell           C. had sold            D. had been selling

                                                                                                参考答案：1-5. CBABD