Don't forget - there are two dialects of Welsh - the North Wales/S4c/BBC dialect- as spoken North of Brecon and West of Camarthen, and Soputh Welsh. Different spellings, difernt pronouciations.That is why the South Welsh and the North Walians need Enlish as a common tounge to communicate in.
Secondly - These differences spread over in to religion. If a Welshman was marooned on a desert Island he/she would build two chappels. One is the Chappel he/she goes to, and the other is the Chappel he/she does not go to.
Garydd.