@Shannon In Bulgaria, the head shake isn't too hard. As an American, it's all about realizing that when others seem like they might be shaking their heads "no" they are actually confirming or agreeing with you with a "yes" head shake but as a foreigner, if you do a western head nod nobody seems to think twice about it. The bigger problem is here in the States. Even if you verbally say "yes" but non-verbally you shake your head "no" because you're confused and you think shaking your head "Bulgarian-yes" would help the situation let me tell you it will not help the situation in America. People who are waiting on you just look at you like you're crazy.