'fraid most of the youngsters round here don't know what a litre is but they do speak Cymraeg (of a sort!)
Perhaps we are more parochial up this way but where I would have (I spell phonetically here) darn o gacan efo fi panad i my friend from the next village to the East would have sleisen o gacen hefo fi paned and their Blaenau is pronounced Blaena' in my village and Bleune in Blaenau!
Even round this way llefrith is dying out in labels etc in favour of llaeth and you can't get buttermilk for love nor money as no one has cows any more. I remember when my daughters were little we visited a farm in the Preselis that was using heavy horses. The farmer and they tried to speak Welsh to each other but in the end they had to revert to English as their versions of Welsh were too far apart.