(particle) Used before people's - names, wai, mea and personified objects when they stand as the subject of the sentence and when they follow i, ki, hei and kei.

(noun) what?

wifi

progress

headache

white cumulus cloud

Pedestrian Crossing

 (pronoun) I, me - like all pronouns and personals, takes a when following ki, i, kei and hei but does not take a when used as the subject of the sentence, except in some dialects. Never occurs after he, te and ngā and is not used after the prepositions a, o, mā, mō, nā, nō or with tā and tō.

ingenuity

River

help!