2. (particle) Used before personal pronouns (except ahau) when they follow i, ki, hei and kei. NB a is pronounced long before koe and ia.
(Te Kākano Textbook (Ed. 2): 57, 83, 102;)
3. (particle) Used before place names and location words when they stand as subject of the sentence.
(Te Pihinga Textbook (Ed. 2): 24-25;)
4. (particle) Sometimes used as a literary device before words that would normally be used as nouns or verbs.
Kāti, kua huri te ihu o tōu ake waka ki Waitematā i runga anō i te āki a rūrūtake, a wheori (HM 2/1992:1). / Well, the prow of your canoe has turned towards Waitematā because of the urging of shaking and quivering of old age.