认识过去完成时与一般过去时的区别(2)

　　2. 表示从过去某一时间开始，一直持续到过去的另一时间的动作或状态。常与for, since引导的表示一段时间的短语或从句连用。如：

　　She had nursed her father in the hospital since she came back.

　　她自从回来以后就一直在医院照顾她的父亲。

　　Mr Smith had taught in Europe for 15 years before he went to Australia.

　　史密斯先生在去澳大利亚之前已经在欧洲教了15年学。

　　3. 过去完成时常用于told, said, knew, heard, thought等动词后面的宾语从句中，表示从句的动作或状态发生在主句的动作之前。如：

　　He told me that he had heard of the good news. 他告诉我说他已经听说了那条好消息。

　　三、 过去完成时与一般过去时的区别

　　过去完成时和一般过去时都可指动作发生在过去，但过去完成时强调动作相对于过去某一时刻已经完成；而一般过去时则强调动作发生在过去某一时间或表示过去经常性、习惯性的动作。如：

　　We had learned two English songs by the end of last term.

　　到上个学期末为止，我们已经学了两首英文歌曲了。

　　We learned two English songs last term.

　　上个学期我们学了两首英文歌曲。

　　四、 过去完成时与现在完成时的区别

　　现在完成时的动作是发生在现在某一时间或动作之前，而过去完成时的动作是发生在过去某一时间或动作之前。如：

　　I have known him for three years.

　　我认识他三年了。

　　I had known him before I was a student.

　　我在上学之前就已经认识他了。

　　[跟踪练习] 根据句意，用括号内所给动词的适当时态填空。

　　1. By the time she was ten, she　　　　　　　 (win) a gold medal in swimming.

　　2. �;I have bought you the books you want.

　　�Oh，good，I was afraid you　　　　　　　　　 （forget）.

　　3. By the time I got home, my favorite sports show

　　(start).

　　4. The bus　　　　　　　　　　　　　 (leave) when I arrived at the bus stop.

　　5. The little girl　　　　　　　　　　 (stay) in bed for almost a month since she fell sick.

　　Key:

　　1. had won 2. had forgotten 3. had started 4. had left 5. had stayed