One would refer to my grandfather's daughter and her husband as my mother and father, assuming he is my biological father and not a step-father.
If your grandfather's daughter is not your mother then her and her husband would be your aunt and uncle. In that case she would be a sister to your mother.
The English language has no special term to describe the grandfather of your son-in-law, and he is not considered to be related to you.
Your grandfather's son is either your father or your uncle. Your daughter's grandfather is your father. or your father-in-law.So your daughter's grandfather is your grandfather's son or a brother if there is more tha one son, or, as your father-in-law, is not related to your grandfather's son at all.
The person is your nephew :)
Your grandfather's brother is your great uncle. His daughter (or his son) is your parent's first cousin and your first cousin, once removed.
Your grandfather's brother's daughter is a 1st cousin of one of your parents. Her son is your 2nd cousin.
Your daughter's daughter's son is your great grandson, and you are his great grandfather or great grandmother.
Your daughter's son is your grandson and you are his grandparent.
Yes.
Your daughter's grandfather's brother's son is her mother's or father's first cousin and her first cousin, once removed.
If you are a male, you are the grandfather, and if you are a female, you are the grandmother of your daughter's son. In other words, you are his grandparent and he is your grandson.
yes because walters grandmothers daughter is walters mother, and if Walter has a son, then his mother is her grandmother, so its true
I'm not sure who Roger is, but yes, the relationship is quite possible. Roger's grandfather's son could be Roger's father; His daughter's grandfather could also be his father, one and the same person. lol