Who's that man?
He's my grandfather.
Who's that woman?
She's my grandmother.
Who's that?
It's / That's my father.
Who's that?
It's / That's my mother.
Is that your father?
No, he isn't. He's my uncle.
Is that your mother?
No, she isn't. She's my aunt.
Who's that boy?
He's my cousin.
Who's that girl?
She's my cousin.
