Lesson
it is difficult to teach slangs. They are informal words used for some people in informal contexts. Slang is a bending that is formed from the words Secret Language, then we have this word. First of all we have to differentiate Slangs from jargon which are words used for Speciafical specialities and proffesions. For intance we can say the jargon of the Doctors (not the slang of the doctors)
some slangs that I have learned are:
Jack/jerk off: verb to masturbate
taking the piss out of you: to bother sb
Dickhead: adj a very stupid person
to come; verb to eyaculate
Prat: a stupid person
Blow Job: oral sex
more information at www.urbandictionary.com