she has a six year old sister,为什么year不加s？

Question

如题所述

Answer 1

我觉得你这样要加s
而six-year-old才不用加s，整个连起来相当于形容词的功能，表示六岁的

Answer 2

你这个写法是不对的，应该是 she has a six-year-old sister.
six-year- old 只能作定语，而 six years old只能作表语，比如 she is six years old.