You are your nephew's aunt/uncle,,, his children are your grandnieces/nephews,, his grandson is your great-grandnephew.
Yes. Your grand nephew, also called great nephew, is the grandson of your brother or sister.
You are a great great Aunt (or Uncle) to the grandson of your Nephew.
Mother's grandson as regards her daughter is either her (daughter's) son or her (daughter's) nephew.
Your brother's grandson is your great nephew.
Your grandson and your nephew are first cousins, once removed.
Your grandson and your great nephew are second cousins to each other.
You are your nephew's aunt/uncle,,, his children are your grandnieces/nephews,, his grandson is your great-grandnephew.
Their cousin, because your child is your nephew`s cousin, so your grandson or granddaughter is also your nephew`s cousin.
Their cousin, because your child is your nephew`s cousin, so your grandson or granddaughter is also your nephew`s cousin.
Your brother-in-law is your spouse's brother. His grandson s your spouce's great nephew. (Some people say grand nephew). That makes him your great nephew, too. Your brother-in-law could also be the husband of your sister. Then your brother-in-law's grandson is your sister's grandson and your great nephew.
Your niece's son is your great-nephew. Your niece's grandson is your great-great nephew.
Your father's great grandson could be your grandson, or your great nephew.
Your nephew's great grandson is your great great great nephew and you are his great great great aunt (if you are a woman) or great great great uncle (if you are a man).
Your sister is your grandson's great aunt. He is her great nephew.
Your grandson is your sister's great nephew and she is his great aunt.
Grandson; nephew.