Who is this?
It's my sister.
Who is this?
It's my father.
Sister
What's this number?
twelve
Who's that?
It's my brother.
Father
Mother
What's this number?
fifteen
Who's that?
It's my mother.
Brother
Is that your mother?
No, it isn't.
Is this your brother? (Yes)
Yes, it is.
Is that your father?
No, it isn't.
Is this your sister?
Yes, it is.