yes it was an honest question and I'm sorry to upset most of the more senstive amongst you , there are different dialects throughout Wales but those of the S east of the principlality are most definately diferent to the rest of Wales, why was and still is the cardiff accent known also as cardiff English and has its roots in similar to the influence of the Liverpool accent. I await a non abusive response
Can you honestly not tell different areas of Swansea by accent? My as is truly tounded! I reckon the whole of the UK is mappable to within about 20/30 miles based on accent and within a particular area, it can be even more pinpointed. Thus I doubted the honesty of your question. But it's certainly not any sensitivity on my part. I've not been accused of sensitivity for a very long time.
Newport and Cardiff accents are very different. This is due to the influence of people from Gloucester and Bristol populating the Newport/Monmouthshire areas many years ago, e.g. my parents' ancestors. There is barely a trace of the Welsh accent in people born and raised in those areas, e.g. me. As for north Walians trying to speak English, either it is the most appalling, guttural strangulation of English ( and you get covered in spit) or pure scouse when they are not speaking Welsh. I agree there can be a scouse twang in the accents of those from some parts of Cardiff but not all.
I said above, common to all big port cities. Due to the migrant populations and settling foreigners. Lots of different accents producing a right bastard of speach.