PronunciationThere are dozens if not hundreds of different ways to speak English. I can't cover all the varieties of accents, dialects and derivations of spoken English in this article. Let's focus on the basics here.
There are two major standards of spoken English -- British and American English. Interestingly enough "RP" ("Received Pronunciation", which is also known as "Queen's English" or "Oxford English") is spoken only by about 5% of the UK population which means there are many different dialects to be found in the British Isles. If you travel the UK you will notice that the differences in pronunciation are stronger and wider than in the US although the latter clearer is the bigger country.
I think this is due to the fact that statistically the average US American relocates more often within the US than his British counterpart. A dialect develops when people live closely together for a longer period of time and the community creates their own unique way of speaking. No doubt people in the southern US states have that distinctive "drawl" whereas people from Boston sound pretty different. But let's focus on the major differences between RP and standard US American English:
Word Stress sometimes is different in both versions:
VocabularyThere are some words and terms that are either used only in British or American English. However, with new media like the internet and in the more internationalized world these words become fewer and fewer.
That's why I'll give you only a selection of the examples I've personally come across. What's really important is not that there are differences but that any British person understands any American without great difficulty and the other way round. I know I'm repeating myself, but please don't forget that British and American English are more similar than different.
Well, we could add to this list a couple of hundred words and phrases and even then the vast majority of the almost 1 million English words would be the same in both versions of English.
Just one last example I'd like to give you here as it might be a bit amusing. The rather colloquial phrase "I'm totally pissed" means different things in British and American English. I won't give you the two different meanings here -- if you really want to I'm sure you'll have your own way of finding out.