新概念第三册第24课复数的问题

Question

We often read in novels how a semmingly respectable person or family has some terrible secret which has been concealed from strangers for years.
其中：..has some terrible secret which has been
这里使用了 some ，但secret 为什么没有用复数形式呢？
24课最后一句也让我困扰。
But George was unsympathetic,"On,that",he said with a smile as if he were talking about an old friend.
既然是 he 那为什么用 were talking? 难道这句话的主语不是 he 吗？

Answer 1

as if he were talking about an old friend.
是虚拟语气。
he were 属于虚拟语气。
仿佛...
he said with a smile as if he were talking about an old friend.
他微笑着说着，仿佛他在谈论一位老朋友（其实事实并非老朋友）
与事实相反，要用虚拟语气。
some secret （ some 有某些、某一个之意，可以接单数可数名词）

Answer 2

secret 本身是有单复数的，可是这句我也没有理解！！
可是下一句，这里是适用了虚拟语气，所以用的是 were talking，而不是was talking.
仅供参考！！

Answer 3

1、has some terrible secret which has been句中的some是adj.中文意思是“某个或另外一个”，因此secret用单数。
2、 as if he were talking about an old friend. 句中as if引导虚拟条件句 因此用were talking。