nau - come, go (as in: Nau mai!)
nāu - you (past tense); yours (singular)
Me tino mārena e koe taku mokopuna nāu hoki is i hapū au.You must marry my granddaughter since you got her pregnant.Simple sentences: you should - me
Nāku tēnei maika, nāu tēnei ārani, nāna tērā tōtiti.This banana is mine, this orange is yours, that sausage is his.Established possession - nāku, nōku...
Nāku, nāu rānei?is this mine or yours?Or... - ...rānei