He is twenty．

He is twenty years old．

He is a twenty-year-old man．

He is aged twenty．

He is at age twenty．

He is at the age of twenty．

He is twenty years of age．

2?表示“在某人几十多岁”，用“in one's ＋基数词复数形式”，例如：

他七十多岁。He is in his seventies．（从70岁到79岁之间）

她五十多岁。She is in her fifties．（从50岁到59岁之间）

还可以借助early，middle，late来表达得更明确一些，例如：

那女孩今年二十二、三岁。The girl is in her early twenties．

他今年十四、五岁。He is in his middle teens．

她今年二十八、九岁。She is in her late twenties．

3?表示“快满多少岁”用进行时或将来时，例如“他快满十八岁了”可说成：

He is getting on for eighteen．

He is going on eighteen years old．

He willbe eighteen years old．

It willbe his eighteenth birthday．

4?表示“不满多少岁”，用副词barely，nearly，al- most，quite，yet，just等，例如“她不满十七岁”有以下几种说法：

She is barely ／nearly ／almost seventeen．

She is not quite ／yet seventeen．

She is just under seventeen．

5?表示“差多久满多少岁”用介词off，例如：

他差5个月就满19岁了。He is five months off nineteen．

她再过3年就50岁了。She is three years off fifty．

6?表示“超过多少岁”用介词past，例如：

他已年过50。He is past fifty．

他是一个过了中年的人。He is a man past middle age．

那孩子两岁零两个月。The baby is two months past two years old．