原书 PDF 第 294—295 页
By the time the doctor arrived the patient had died.
如何分析句中的 by the time?
从结构上看, By the time the doctor arrived 是介词 + 名词 + 定语从句, 即 By the time the doctor arrived = By the time that the doctor arrived。因此, 有一派英语语法学家, 如 R. Quirk 等把它看作是介词短语 + 定语从句, 具有类似于时间状语从句的语义功能。另一派英语语法学家, 如薄冰教授等则把 by the time 干脆看作是从属连词, 引导时间状语从句。
By the time he was twelve, Edison ____ to make a living by himself.
A. would begin B. has begun C. had begun D. was begun(全国高考)
上面的试题要求选 C(had begun)。这是一个考试热点:从句 by the time + 过去时要求主句用过去完成时。但是下面的实例却违背了这个规则:主句用了一般过去时。请解释:
By the time the doctor came, the man was able to sit up, but he still looked pretty sick.
当 by the time 从句用过去时时，主句通常用过去完成时。这时 by the time... 表示“在……之前”“到……的时候”，而主句则表示在此时间之前某个事件业已完成。当从句为一般现在时，而主句为将来完成时，情况亦是如此：
By the time I got to the station the train had already gone. 我到达火车站时,火车已经开走了。
By the time he was fourteen years old, he had learned maths all by himself. 到他14岁,他已经自学了数学。
By the time you come back, I'll have done my homework. 在你回来以前,我的作业会都做
完的。
但是,当 by the time 用过去时时,主句有时也用一般过去时,这时 by the time 常常表示“在……的时候”“到……的时候”。当 by the time 从句用一般将来时,而主句用一般现在时或现在进行时,情况亦是如此:
By the time we'd walked five miles, he was already exhausted. 当我们走了五英里的时候，他就已经筋疲力尽了。
By the time her breakfast tray came in Bright was ready for the comfort of food and hot coffee. 等早餐端进来时，布赖特已准备好享受一顿美餐和热咖啡了。
By the time the alarm went off, I was awake. 当闹钟铃响的时候，我在醒着。
By the time he was taken to the hospital he was nearly dead. 他被送到医院时已经几乎不行了。
By the time he was fourteen, he was able to teach himself advanced maths. 到了十四岁，他能自学高等数学了。
I shall be away by the time (that) the clock strikes twelve. 钟敲 12 点的时候, 我就要走了。
By the time they caught up with us, they were sopping wet but otherwise none the worse for wear. (Hillary, Living History) 他们赶上我们时，已经全身湿透，不过好在没有受伤。（希拉里，《亲历历史》）
By the time he was twelve, Edison had begun to make a living by himself. (全国高考) [原译]爱迪生到12岁时，不得不自己去谋生。（《历届高考英语选择题详解》，学苑出版社，p.121）
译文的意思显然是指“爱迪生12岁时才开始谋生”，不知这是否符合原意？
by the time (that) 可以看作是引导时间状语的从属连词。当它所引导的时间状语从句与主句的过去完成时并用时，表示主句的动作在从句所表示的动作或状态之前业已完成：
By the time he got married he had studied history ten years. 到他结婚时,他研究历史已有10年了。
By the time he arrived, we had already left. 他到达时,我们已经离开。
因此，在上面的高考英语试题中，主句的动作(had begun)先于从句所表示的状态(he was twelve)，因此，似应译为：爱迪生在12岁之前就开始自己谋生了。
这种译法是符合历史事实的：“When he was ten Edison built his own chemistry laboratory. He sold sandwiches and newspapers on the local trains in order to earn money…”（爱迪生在他十岁时建立了自己的化学实验室。为了赚钱，他在当地的火车上卖夹肉面包和报纸……）