- 1. [adj-no, adj-na, n] optional; voluntary; arbitrary; random; discretionary; facultative; spontaneous; any
- 2. [adj-no, adj-na, n] {math} arbitrary
Conjugation — Adjective (―na)
This word itself does not change -- these are forms of the copula だ ("to be") attached to it.
| Attributive (before a noun) | にんいな | (ninina) |
| Non-past, plain | にんいだ | (ninida) |
| Non-past, polite | にんいです | (ninidesu) |
| Past, plain | にんいだった | (ninidatta) |
| Past, polite | にんいでした | (ninideshita) |
| Negative, plain | にんいじゃない | (ninijanai) |
| Negative, polite | にんいじゃないです | (ninijanaidesu) |
| Past negative, plain | にんいじゃなかった | (ninijanakatta) |
| Past negative, polite | にんいじゃなかったです | (ninijanakattadesu) |
| Te-form | にんいで | (ninide) |
| Conditional (―nara) | にんいなら | (nininara) |