i am personA's aunt
Your grandfather's brother's grandson is your great uncle's grandson. The grandchildren of great aunts and great uncles are your second cousins.
Your grandfather's sister is your great aunt.
Cousin
Your cousin.
yes, you can. If your dad and your cousins mom are brother and sister then you can date your cousins cousin on your cousins dads side.
Your grandfather's children are either your parents or aunts or uncles.
First cousins, twice removed. Aunts daughter is your cousin. Aunts daughters daughter is cousin once removed Aunts daughters daughters daughter is cousin twice removed.
Your first cousin.
Your are related to some of your first cousin's aunts and not to others. The aunts of your first cousin to whom you may be related are your mother and her sisters or your father's sisters. One of the parents of your first cousin isn't related to you, but married into the family. Anyone of your cousins aunts who are related to that person would not be related to you.
Her aunts/uncles daughter.
They'd be your cousin.
Your Aunt's first cousin may be your second cousin, onve removed or may be no relation to you at all.