Language/Volapuk/Grammar/plural

To form the plural, simply add -s to the end.

• dom, doms ‘a/the house, the houses’
• säk, säks ‘a/the question, the questions’
• labob dautis tel ‘I have two daughters’
• voms binofs sörs ‘the women are sisters’

Source: http://www.xn--volapk-7ya.com/quick-look-at-volapuk.html