The dual signals that two entities are involved. It can be marked in two different ways:
i) The verb is repeated once.
ix3x+3y-pl clean sweepx sweepy punish.
‘Both of them are punished to sweep (the floor).’
(based on Ribera, 2015: 385)
ii) In the case of one-handed signs, the non-dominant hand can be added in the articulation of the verb in order to express the dual plural. When the non-dominant hand is added and articulated at the same time it means that the two actions occurred at the same time.
dh: take
ndh: take
(based on Ribera, 2014: 383)