This is one of those questions that overwhelms a native English speaker because we don't even know where to begin. So I googled "most common slang terms" this page came up first. It seems like a good place to start. http://www.uwplatt.edu/university/documents/international_student_handbook/slang.pdf Also, if there is something you hear but don't understand and you're guessing it's slang you can look it up in the online "urban dictionary." A caution with this one though, it has really a lot of profanities and possibly offensive content since it's a slang dictionary.

slang in English ? ?

There is a very wide range of slang in English. IT goes from the common "wanna" & airhead, backstabber, chill, dough & such through to the rubbish suggested to be words & meanings on the urbandictionary website. Each country has shared & individual slang. Australia has a large number of slang expressions which seem little-used elsewhere. There are many books & website with slang lists. http://www.manythings.org/slang/ http://www.infosquares.com/americanslang/americanslang.html