sáðuna comes from the Medieval Greek ísa ‘exactly’ and the Lesbian local adverb éðuna ‘here’ (eðó + na) (Ralli 2017, Ralli 2019).
E.g. sáðuna ídan. pú píʝi tóra? ísa-eðó-na ítan. pú píʝe tóra? ‘It was here. Where is it now?’