Dydh Tregedna by Cornish Language Office Please be aware that attendees need to book by Saturday 15th February. Kosten Dydh Tregedna yw kewsel Kernewek hepken oll an jydh. The aim of a Tregedna Weekend or Day is to speak only Cornish all day. It’s an opportunity to use your Cornish. So, to attend this day you ought to be able to take part in simple conversations.