On-line Te Reo Māori Dictionary

Ko Pita te mokopuna tuatahi.
Pita is the first grandchild.
Identity sentences - ko...

Ko James te tamaiti tuarua o te whānau
James is the second child in the family.
Ordinal numbers (First, second, third...) - tuatahi, tuarua...

Ko James Tait tōku tipuna.
James Tait is my ancestor.

Arā a Hēmi e oma mai ana.
There is James running.