Ko Joseph te tuakana o Isaac.Joseph is the elder sibling (of the same gender) of Isaac.Family relationships - older sibling of the same sex - tuakana
Ko Ataahua rātou ko Honi ko Kauri āku tamariki.Ataahua, Honi and Kauri are my children.Talking about more than one person - ...rāua ko..., rātou ko...
Ko Joseph te mātāmua o Phill.Joseph is the oldest child of Phill.
Ko Joseph te mātāmua o āku tamariki.Joseph is the eldest of my children.
Ko Joseph taku tamaiti.Joseph is my child