My birthday is (june 13th)(对括号部分提问）
When is your birthday?
That girl is (thirteen)(对括号部分提问)
How old is the girl?
We have a volleyball game (in March)(对括号部分提问)
When do you have a volleyball game?
How old is your brother?(改为同义句)
What's your brother's age?
His birthday is September 21st.(改为同义句)
The date of his birth is September 21st.