1.他三十歲：He is thirty (years old)./ He is thirty years of age./He is aged of thirty.
2.他已經三十歲了：He is already thirty./He has reached the age of thirty.
3.一個三十歲的男人：a thirty-year-old man/ a man who is thirty/a man of thirty/ a man aged thirty/ a man at the age of thirty
1.他年近三十歲了：He is nearly thirty./He is near to thirty./He is toward thirty./He is getting on thirty./He is hard on thirty.
2.他三十好幾了：He is in his middle thirty./ He is well over thirty.
3.他與我同歲：He is as old as I am./ He is as old as me.
1.她看上去比實際年齡小：She looks younger than her years.
2.她看上去比實際年齡小十歲：She looks ten years younger than her real age.
3.我年紀比你大：I am older then you.
e.g. I appreciate that. Speaking of which, I was wondering if I am older than you, because you look so young.
4.她三十歲了，但看上去才二十歲：She is thirty but looks twenty.
e.g. She is thirty but she appears young.
1.一個未成年人：a youngest/ a teenager/ a juveniles/ an adolescent/ a minor
2.一個成年人：a grown-up/ an adult/ a person of mature years
3.一個中年人：a middle-aged man/ a man of middle age
4.一位老人：an old man/ am elderly man/ an aged man/ a man in his old age