I am not a native english speaker. I have been speaking english for 5 years. I have American friends and Friends the UK. It's easy to tell the difference between American English and British English. I am sure English varies within the united kingdom, The BBC news typically uses the English from the very south of the UK. Just to be clear, The U.S. have different accents within "the American tone". I have been in " THE SOUTH ", and they speak loud and they roll their vowels ( I could not understand anything at the beginning). I think the US is big and has different " tones" based on the location. States like (N&S) Dakotas, Texas, New York, Brooklyn are all distinct tones. Note: British and American English have different words for different things like, apartment = flat, elevator = lift, exc... I hope that was informative. I'm not sure if I answered your question because your question is very general.