Donja Lomnica sits in the Zagreb basin where the standard Croatian (štokavski, ekavian) dialect is spoken, with subtle local intonation patterns common to the Moslavina–Turopolje region. Younger residents in Velika Gorica often speak functional English, but in the village and at family-run guesthouses, Croatian is the default, and a short phrase often earns a warmer response.
Croatia has used the Euro (EUR) since January 2023, and 112 is the single EU-wide emergency number. Signs in Donja Lomnica are almost exclusively Croatian; learn the basics for bus stops (autobusna stanica), the post office (pošta), and the parish (župa) before you set out.