ten years old,ten-year-old的区别
答：两种年龄表示法。一种是“数字+years old”，作表语：
My father is fifty-seven years old now.
我父亲现在已57岁了。
另一种是“数字+ -year-old”，作定语：
Last week, my four-year-old daughter, Sally, was invited to a children's party.
上周，我4岁的女儿萨莉应邀去参加一个儿童晚会。
由上可知，ten years old常用来作表语，ten-year-old常用来作定语。
