关于who引导的定语从句；

Question

1)a large number of men always around a girl who is my friend.
2)a large number of men always around a girl, the girl who is my friend.
3)a girl was always arounded by a group of men who is my friend
4)a girl was always arounded by a group of men ,the girl who is my friend
5)my brother always arounds a girl who is my friend
6)my brother always arounds a girl, the girl who is my friend
7)a girl was always arounded by my brother who is my friend
8)a girl was always arounded by my brother, the girl who is my friend

求高手给我解释一下上面那几句话是对的，他们正确的意思是什么？小弟我看的晕了
当主句有两个以上的人物时从句是不是一定要加The girl，否则就是指代不清？

Answer 1

1)a large number of men always around a girl who is my friend.
4)a girl was always arounded by a group of men ,the girl who is my friend

正确，意思是一群男人老是围着一个女孩，那女孩是我朋友。
5)my brother always arounds a girl who is my friend
8)a girl was always arounded by my brother, the girl who is my friend

正确，我哥哥老是围着一个女孩，那女孩是我朋友。
2)a large number of men always around a girl, the girl who is my friend.
6)my brother always arounds a girl, the girl who is my friend
错误，不应该加the girl 因为先行词a girl
跟从句时紧挨的
7)a girl was always arounded by my brother who is my friend
3)a girl was always arounded by a group of men who is my friend
错误，这种情况应该加the girl
否则它就指代的是my brother ，a group of men
定语从句的构成 先行词（名词）+ 引导词（关系代词 关系副词） + 定语从句
用结构分析，自己体味，语感也很重要的。

Answer 2

第五句可以 语法没错 但是读着别扭

你想说的是 我的哥哥总是围在一个女孩的周围 这个女孩是我的朋友

最简单的说 记住定语从句的构成 先行词（名词）+ 引导词（关系代词 关系副词） + 定语从句
这个是定从的最基本格式 初学定语从句 出了这个格式 就错