Again American and British varieties are evolving mostly independently of each other
Brits are exposed to vastly more American usage than the other way around.
Given the communication facilities that exist in the modern world, it wil be interesting to see if both versions of English evolve to the extent that they become unintelligible to each other one day.
For me as a non-native speaker British English and American English have already become different languages orally, but they are still unity as far as writing is concerned.