1. (particle) here - used after nouns, location words, pronouns and personal names to indicate position or connection with the speaker or the principal character in a narrative. Like the other two locative particles, nā and rā, it follows manner particles (i.e. kau, kē, noa, rawa and tonu) and directional particles (i.e. mai, atu, iho and ake) in the phrase if they are present.
(Te Kākano Textbook (Ed. 2): 44;)
2. (particle) Also used to imply nearness to the present time, or a time or event just referred to.
Ka whakawhiti rāua ki Te Ika-a-Māui i te rā nei. / They cross to the North Island today.
I karangahia tēnei ko Te Heke Hauhaua, ā, ko Te Kāeaea tonu tētahi o ngā rangatira. Koia nei pea te wā i hoki ai a ia ki Te Wairarapa (TTR 1990:202). / This was called Te Heke Hauhaua and Te Kaeaea was one of the leaders. This was probably the time that he returned to Wairarapa.
7. (particle) Used before koa and rā to introduce explanatory sentences.
8. (particle) here - often starts a sentence.
Nei ka noho, ka noho, ka mahuki ake a whakaaro tērā pea ka whai hua tonu te wero atu ki te pātai, "He aha ia tēnei mea, te mātauranga Māori?" (HM 1/1998:2) / Here I sit and sit, and thoughts spring to mind that perhaps there is value in challenging with the question, "Just what is this thing Māori knowledge?"
9. (particle) on and on - used to indicate a long duration when the phrase with nei is repeated.
Ka mea atu tērā, "Waiho rā kia toru hoki ngā pō e rere ai, ā, ka kore e kitea te whenua, ka hoki ai tātou." Ka whakaae mai ngā hoa. I rere nei, rere nei. Kua tata ki te whenua (MM.TKM 1/11/1855:9). / That one said, "Let us wait and sail for three more nights and if we not don't find land we will return." The companions agreed. So they sailed on and on. Then they were near land.