“高中英语课本第一册137页有这样一句话: It had been fifteen years since she left! 我不理解为什么这句话的主句用过去完成时, 而从句用过去时, 好像换成: It was fifteen years since she had left! 合适些。您说对吗?”(转引自《英语难题解答400则》)
《英语难题解答400则》(p.199)已经对这个问题作了回答。我们将用另一种完全不同的方法进行回答。
A. 当 since 表示从过去的一个时间点延续至说话的现在时, 通常要求主句使用动词的现在完成时, 而要求 since 从句使用一般过去时:
-
We've been friends ever since we left school. (LASED) 自从我们毕业以来我们一直是朋友。
-
Since I was a child I have lived in England. (Shaw) 我从童年时起就一直住在英国。
-
It has been about forty years since a person could turn in paper money and get gold for it. 大约已有40年人们不再能在银行里用纸币换黄金了。
但是,当主句的谓语动词为 be 或 seem 时,则主句可以采用动词的一般现在时,当 be 与表示时间的词语连用时,尤其是如此:
-
It's a long time since I met you last. (Snow) 我们已经分别很久了。
-
It seems a long time since we last met. (CGEL) 自从我们上次见面以来似乎过了很长时间了。
那么,从句的动词时态是不是只能采用一般过去时呢?并不是这样。从句中的动词时态分两种情况:当 since 从句所指的是主句事件发生的起点时,从句通常使用一般过去时,如前面的例(1)和例(2);当 since 从句所指的是一直持续到现在的一段时间时,从句通常使用现在完成时:
-
I haven't seen you since I've been back. (Hemingway) 我回来以后一直没有见到你。
-
Since they have lived in London, they have been increasingly happy. (CGEL) 自从他们住到伦敦以来,他们越来越高兴。(他们现在仍在伦敦。)
-
He has never been to see me since I have been ill. (Wood) 自从我有病以来他一次也没来看我。(我现在仍在病中。)
如果主句为 时间词语结构,则主句仍然可以用一般现在时:
It's some considerable time since I have spoken to you on these matters. (Snow) 自从我和你说过这些事以来已经有不少时间了。
这样,对于我们所讨论的情况,主句与从句的时态便有四种不同的组合(例句如上):
a) 主句现在完成时 + 从句一般过去时
b) 主句一般现在时 + 从句一般过去时
c) 主句现在完成时 + 从句现在完成时
)主句一般现在时 从句现在完成时
B. 当主句所表示的情境属于过去时,也就是说 since 从句所涉及的情境不是延伸到现在,而是从过去的某个时间点延伸到另一个过去的时间点时,主句一般采用过去完成时。但是,可以用一般过去时来代替过去完成时,当主句为 be+ 时间词语的结构时,尤其如此:
-
Two weeks had passed since Martin had seen him. (London) 马丁看见他以后已过去两周了。
-
Since the country had achieved independence, it had revised its constitution twice. (CGEL) 自从这个国家独立以来,已经两次修改了宪法。
-
It was years since I had seen her. (Snow) 我和她见过面以后有好几年了。
-
Since mother died he was very lonely. (Dreiser) 自他妈妈去世之后他一直很孤独。
在这种情况下, since 从句既可以使用过去完成时, 也可以使用一般过去时:
-
Since Jennie had left Martha had married. (Dreiser) 自从珍妮离开后,玛莎就结婚了。
-
Since she came to me, we had been happy. (Snow) 自从她来到我这里,我们都很高兴。
-
Since he knew her, she was a journalist. 从他认识她的时候起,她就是个新闻工作者。不难看出,在这里,主句与从句的时态也有四种组合:
a) 主句过去完成时 + 从句过去完成时 (例句 1,2,5)
b) 主句过去时 + 从句过去完成时(例句 3)
c) 主句过去完成时 + 从句过去时(例句 6)
)主句过去时 从句过去时(例句4,7)
很容易发现,这四种组合是前四种组合的时态前移,即一般现在时前移为一般过去时,现在完成时前移为过去完成时。例如:
It is years since I saw you. 自从我上次见过你已有好几年了。
It was years since I had seen you.
由此可以证明,高中英语课本中的句子 It had been fifteen years since she left! 是完全正确的。你将它改为 It had been (或 was) fifteen years since she had left! 也是完全正确的。
They asked me to have a drink with them. I said that it was at least ten years since I ____ a good drink.
A. had enjoyed B. was enjoying C. enjoyed D. had been enjoying(全国高考)
正确答案为 A(had enjoyed)。但是我认为 C(enjoyed) 也是正确的。
关于 since 从句的动词的时态, CGEL 作了明确的说明:
“When the whole period is placed in past time, the past perfective or the simple past is used in the since-clause.” (CGEL, p. 1018) “当整个时间段位于过去时间时, since 从句可使用过去完成时或过去时。”下面是我们收集到的 since 从句使用动词过去时的例句:
-
Since the country (had) achieved independence, it (had) revised its constitution twice. (CGEL) 自从国家独立以来,已经两次修改了宪法。
-
It was ages since they last paid their bills on time. (CGEL) 自从他们上次按时付清账单以来,已经过了很长时间了。
上面的高考题,如果选 C(enjoyed),则其结构与例(2)完全相同。可见,选 C 是完全正
确的。
(参见 since 条中的例句)