six-year-old和six years old用法有什么区别?
问题描述：
six-year-old和six years old用法有什么区别?
答
six-year-old 比如 she is a six-year-old girl。
但six years old 的相等例句是 she is six years old 。前面不用冠词 “a”后面也不用加名词“girl”。
答
six-year-old是作前置修饰语用的，比如，my six-year-old sister, 而six years old通常用在系表结构当中，比如，My sister is six years old.
答
前者可当adj.用 She is a six-year-old girl.
后者当表语 She is six years old.
答
没有区别，完全相等，只是因为有了连字符“—”，所以就不用复数了~