This wasn't available on UK Amazon - pity - but it did remind me I could use YouTube (doesn't matter how many times it happens, but I never think of using the internet unless I am reminded to). And what I found there amazed me. There was one video that illustrated accents for every US State. I didn't even the slightest problem with ANY of them, and I'm 75% deaf. I rarely watch tv so I'm not exposed to American speech all that much, and I've only been to about half of the states in person. So why can I cope with their accents and they can't cope with British accents?People interested in US speech might find a lot of information in the book American Voices by Walt Wolfram and Ben Ward : https://smile.amazon.com/American-Voice ... 618&sr=8-7
I don't have any special gifts. I think most Brits would have a similar take on it to me. But many Brits do have problems with other Brits.
My first thought on this is that all Americans are speaking the same language, and just have different accents and, especially, intonation. But in Britain there is actually a divide between two languages: a group dominated by Old Northumbrian, which covered an area from Scotland down to central England, and a group dominated by Mercian, which covered the extreme south. They were separate languages because they had separate grammars. Despite atrophy over time, they have strong residues, which means northern speech differs not just in accent or intonation but also in grammar, idiom and vocabulary.
There are also some surprising influences from Celtic languages on northern speech. For example, I don't normally use the word movie. I write film. But I say fillum. This insertion of an extra vowel applies to many similar words. It comes from Gaelic. The use of hard and soft consonants that will be familiar to some from Russian (and quite a few other languages) is a strong feature of Gaelic and crops up in the speech of non-Gaelic people. E.g. I say (when not speaking "proper" English) fyess for face. There are also some word-order differences from Gaelic. I personally am not familiar with contributions from Welsh, but I know there are some. So all in all, maybe British people have more on their plate when dealing with other Brits.
These two strains of language were undoubtedly taken to America, but my guess is that people from mixed origins moved round there more freely and widely, and so the atrophy developed at a faster pace.
There may be some cultural differences, too. People, especially children, like to differentiate themselves. American children don't wear a school children and can be as different in dress as they like (or at least that is my impression). British (and Commonwealth) children have to wear school uniforms. Maybe they like to differentiate themselves through language????