Forget about German Schnitzel. Schweizer Schnitzel beats it anytime. (Hai Junes ))) )
Don't say anything about Nazis when anyone older than 18 years is around. Do not do the "greeting." Don't go to the districts Neuköln or Kreuzberg when you're in Berlin. Avoid saying "Jew" or "Jude." Most people might think you're talking about gassing them. If one of your classmates does anything stupid, walk away. Quickly. Otherwise, learn the basic German phrases as listed somewhere above. Be friendly and we'll be friendly back. And if you have questions, add me on Skype. My name's in my profile.
