Originally Posted by
Eastbay1K
...
Ser becomes "sos" - żVos sos estadounidense?"
Maybe in Chile they're that polite! Expect to be called a yanqui "shankee" (from yanquilandia of course).
Wiki has a brief synopsis of castellano rioplatense:
http://en.wikipedia.org/wiki/Rioplatense_Spanish
żDe donde sos?
http://www.youtube.com/watch?v=3wDBEWTSlH0