some 后的词不加s 的情况，应该是属于不可数名词。如：some time /water /juice 等。

some既可以修饰可数名词，例如: some books也可以修饰不可数名词,例如 :some water

例句:

To many, a legend must be a story, with characters and some sort of plot.

其中绝大部分人认为都市传奇必须是一个有人物有情节的故事。

一般而言，“(a/an)+(若干前置修饰语)+名词+of+限定词+sort(s)/kind(s)”和“限定词+sort(s)/kind(s) of+(若干前置修饰语)+名词”可以相互替换，

比如：

• a game of some sort = some sort of game

• things of all sorts = all sorts of things

• people of this kind = kind of two people

• pain of any kind = any kind of pain