Age

Typical mistakes: 

He has thirty-five. 

He is thirty-five years. 

He's thirty-five old. 

You can give your age either by just giving the number, or by giving the number plus the expression 'years old'. Note the use of 'Be', without preposition. 

He's thirty-five. 

He's thirty-five years old. 

Note that 'What's your age?' is not a very common expression except in a formal style. People usually say 'How old are you?'