两种年龄表示法：

一种是“数字+yearsold”，作表语：

My father isfifty-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。