Quote Originally Posted by Throbert McGee View Post
Я родной коренной сын Пнидостана -- American English is my native language, but I greatly respect Hanna's authority on English, especially in respect to British usage, but also in respect to English overall. If you have a very specific question about American slang, then perhaps you should ask me instead of Hanna -- but if your question is about British slang, then Hanna can probably give you better advice than I can.
You are right - occasionally I come across American slang expressions I don't know.
It doesn't happen in films, but on the rare occasion I tune in to a US reality shows I've come across it.

There is a whole host of US words which are never used in England. "Oftentimes" (is that really a word?!) or "my bad" are some off the top of my head are really common. As well as endless business jargon inspired by baseball or American football. It assumes you know the rules of these games and the related vocabulary, which I don't...

My view on slang is that it is to be used only by native speakers, or people who are native AND have lived in the country in question for at least 10-15 years. I have learned this lesson the hard way, hehe...