-nga
1. (particle) A suffix used to make verbs into nouns sometimes called derived nouns. Commonly used with verbs that do not take a direct object and take the passive ending -a and -na, statives and adjectives. These nouns usually mean the place or the time of the verb's action.
(Te Pihinga Textbook (Ed. 2): 88-89, 123-124;)
2. (particle) A passive ending used with only a few verbs ending in -ai.
(Te Kākano Textbook (Ed. 2): 65-67, 84-85;)