"Cò mheud? Naoi deug?"
Translation:How many? Nineteen?
Are you sure you didn’t make any other mistake? Or maybe it was a listening exercise (you’re supposed to write exactly what the speaker says in those, not any alternative sentence)?
Also – I don’t think I’d call cia mheud the ‘modern’ form – they’re just both used in parallel (and I’d argue cia mheud is actually the more conservative one).