There are great differences between the two countries. Americans are generous and enthusiastic, while the British are introverted and conservative, which affects their character.

There will be some changes in pronunciation. Americans are very casual, and their intonation will be exaggerated, especially when they start syllables.

However, some words seem to be used only in the United States or Britain, probably because of differences. Who knows, it should be a matter of two countries. And their cultural systems are different, which should have a certain degree of influence. I hope it helps you, hehe.