both of us .可以改成both of 为什么?请说明规则 很着急!

题目

both of us .可以改成both of 为什么?请说明规则 很着急!
her parents are both teacher.
both of her parents are teacher.
请告诉我这两种类型应该怎么学会?有什么方式,格式?规则?
有什么办法学会造这两个句子?

答案

both of we是不行的,因为of是介词,后面要用宾格
her parents are both teacher.
both of her parents are teacher.
这两句是正确的,因为偶发后时名词,名词既可以作主语,也可以作宾语