Yes in North and South, the accent in the north is spoken more quickly, the South drawls , no different to England I suppose, so the way some words are pronounced may sound differently but I was brought up in South Wales with a Grandfather from Anglesey. We never had cause to ask what one word meant. I pronounce some place names in Anglesey differently to my friends in the north . Never met one 'how green was my valley ' accent in my life, doubt the makers of that film had either