Talking about age

Use of be

We most often talk about people’s ages with be + number

• He is thirty. (not He has thirty.)

or be + number + years old (more formal: … of age).

• He is thirty years old / of age. (not … thirty years.)

We ask How old are you?, not normally What is your age?

be + … age

Note the structure be + … age (without a preposition).

• When I was your age I was working. (not When I was at your age …)
• The two boys are the same age.
• She’s the same age as me.

Prepositions

In other structures, at is common before age.

• He could read at the age of three. (not … in the age …)
• At your age I already had a job.