until 的用法…具体例子didn't know anything about it until you told m

until 的用法…具体例子
didn't know anything about it until you told me
until the manager returns ,nothing can be done .
大家看上面两句,第一句用否定形式,说是终止性动词必须用否定,我想问一下是指那个动词?know 还是until 后的told
第二句要用否定词是看那个动作?和第一句有什么区别?return 也是终止性,为什么不用否定?
请认真看我的问题再回答,不要发一大堆语法过来!我这里有很多语法书!