Your great aunt's son is your parent's first cousin and your first cousin, once removed.
Your grand niece's son is your great grand nephew.
Your sister's son is your nephew His sons are your grandnephews, and his daughters are your grandnieces.
Your aunt is your children's great aunt, and they are her grandnieces and grandnephews.
Your sister's son is your nephew His sons are your grandnephews, and his daughters are your grandnieces.
Your grandniece's daughter is your great-grandniece.
granduncle - grandnephews/grandnieces
Your daughter and your grandneice are First cousins, once removed.
Abel was killed before he had a chance to marry. Adam's unnamed sons (Genesis ch.5), and Seth, married nieces and grandnieces. Cain, who was the first son of Adam to get married, had no choice but to marry one of his sisters (Rashi commentary, Leviticus 20:17).That isn't clarified in the Bible.
You are your nephew's aunt/uncle,,, his children are your grandnieces/nephews,, his grandson is your great-grandnephew.
The plural of grand niece is grand nieces.
Your sister's son is not related to your husband's sister's son, because they share no common ancestor.
You brother is your grandchildren's great uncle or granduncle.Your grandchildren are your brother's grandnieces and grandnephews
No. Your sister's husband is your brother-in-law, but his sister (and her son) are not related to you. However, that son is your sister's nephew.