 (na-)
ro=na-biri=ʔia
3PL=REAL-work=3SG
‘They did it.’

whereas an irrealis mood/marker doesn't convey a past tense.ro=ʔa-biri=ʔia
3PL=IRR-work=3SG
‘They are about to do it.’

Wuvulu negation can be broadly divided into verbal negation and clausal negation.Verbal negation in Wuvulu takes the form of an inflectional morpheme.