Question

改错,下面句子如何改错？

The boy is in his twenty.

Answer 1

The boy is twenty
　1表示“整岁”，直接用基数词或year，age，例如“他20岁”可表示为：
　　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 ones ＋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.

Answer 2

第一，正确的改正：将in 改为at，改后的句子就是：The boy is at his twenty.意思就是The boy is twenty.这个男孩20岁了。
第二，in hs twenty,表示的意思：一个不确指的时间段，二十几岁的意思；
而at his twenty，意思是年龄点，相当于twenty。

Answer 3

twenty---twenties

Answer 4

The boy is on his twenty