Your father's father is your grandfather.
Your grandfather's brother is your great uncle.
Your great uncle's son is your fahter's first cousin and your first cousin, once removed.
Yes, she did. She had the relationship of a mother that a mother has with her son. As most mothers do.
Your mother's son is your brother or your half brother.
She is your third cousin.
Your mums brothers sisters roommate flatmates sisters brothers mothers son.
Great uncle / Great nephew
You are their aunt or aunt by marriage.
Do something nice for next mothers day
Your mother's aunt's son is her first cousin and your first cousin, once removed.
No because that would be your cousin
He would be your first cousin once removed; also, he would be the second cousin of your son.
Step-brothers
Your grandson is the great-nephew of your brother.