Ko Isaac te teina o Jo.Isaac is the younger sibling (of the same gender) of Jo.Family relationships - younger sibling of the same sex - teina
Ko Isaac te pōtiki o Phill.Isaac is the youngest child of Phill.Family relationships - youngest - pōtiki
Ko Isaac te tama a Phill rāua ko Angie.Isaac is the son of Phill and Angie.Talking about more than one person - ...rāua ko..., rātou ko...