在全新版《大学英语》(上海外语教育出版社)第一册第三单元Understanding Science里有这么一句：The science people learn in school can provide the basic framework.But the rate of scientific progress is now so rapid that there are always new developments that have occurred since one was at school or university.学生对句中since-从句的用法颇感困惑,如译为"自从我们在学校或大学里"似乎与前句意思相矛盾。不错,是有矛盾,内容与形式的矛盾。这里涉及到since-从句和持续性动词的用法问题。本文就着重分析这个问题。

　　在平时的阅读、写作中,可见大量这类句子：

　　I haven't seen him since he left Shanghai.

　　I've been waiting since the plane landed.

　　She has been working in that company since she came to this city.

　　He has been studying linguistics since he went to the United States.

　　在主句是现在完成时,从句是一般过去时的条件下,since-从句连接非持续性动词,可照字面意思翻译。而同样的条件下,since-从句和持续性动词连用,持续性动词的一般过去时,表示动作或状态的结束,计时的起点应是动作或状态的结束之时,其含义恰好和动词的词义相反,因而具有否定的意味,即否定的内容寓于肯定的语法形式之中,翻译的时候,就不能照字面直译了。例如：

　　The house has been in bad repair since he lived in it.

　　在此例句中,lived是表示持续性动作,按上面分析,应该是表示该动作的结束,意思上相当于didn't live or moved out,因而可译为：自从他搬走后,房子破烂不堪。又如：

　　We haven't seen each other since we were in the same company.自从我们离开了同一家公司后,彼此就一直未见过面。

　　这里were是表示状态的持续性动词,它的实际意思应是"不在",即"left"。

　　再看其它例子：

　　He has written to me frequently since I was ill.自从我病愈以来,他经常给我来信。

　　通过上面的分析,就不难理解文章刚开始的那个句子。该句就应译为"人们在学校学到的科学知识可以提供一个基本的框架。但如今科学进步的速度如此之快,一个人离开学校或大学后新的发展层出不穷。"

　　since-从句还可与持续性动词的现在完成时连用,其内容形式是一致的。例如：

　　I've smoked since I've been in this company.

　　我来这家公司后一直抽烟。

　　He has been here since he has lived next door to us.自从他住在我家隔壁以来,他一直在这里。

　　(文/浙江青年学院李建红;英语通大学英语四级考试版03~04学年第10期;版权归英语辅导报社所有,独家网络合作伙伴新浪教育,未经许可,不得以任何形式进行转载。)