In England - which you might recall, is where the English language is from - they say “in hospital” and many words that we spell with “or” they spell with “our”. This is the country and culture that gave us Shakespeare and the King James translation of the bible - and even our Declaration of Independence and our constitution comes from English writing and philosophy.
They also say “...at table...” and use their fork with their left hand, upside down...just a few social differences we might acknowledge.
I've been to England. The people there were almost incomprehensible.
We may have started out with the same language, but it has evolved considerably since we parted ways. As a result, most dialects of American are comprehensible, while most dialects of British are not. Our pronunciation, spelling, grammar, and word usage are all quite different.