He is my father's father.
grandfather
She is my mother's mother.
grandmother
They are my father's parents.
grandparents
He's my mother's brother.
uncle
She's my father's sister.
aunt
They are my uncle's children.
cousins
He is my aunt's husband.
uncle
She is my uncle's wife.
aunt
He is my son's son.
grandson
She is my son's daughter.
granddaughter
They are my son's children.
grandchildren
