source: The geographical profile of Welsh in the 2001 Census confirmed this pattern, with a decrease in the percentage of those able to speak Welsh in traditional heartlands such as Anglesey, Carmarthenshire, Ceredigion, Conwy, Denbighshire and Gwynedd. 
target: Gwnaeth proffil daearyddol y Gymraeg yng Nghyfrifiad 2001 gadarnhau’r patrwm hwn, gan fod canran y siaradwyr Cymraeg wedi lleihau mewn broydd Cymraeg traddodiadol fel Ceredigion, Conwy, Gwynedd, Sir Ddinbych, Sir Gaerfyrddin ac Ynys Môn. 