There have been a couple of occasions where I've talked to Koreans and they were "hurt" by the expressions I used even though I meant no disrespect whatsoever. Once it happened with a taxi driver and the other with a store clerk and in both occasions I said to myself "This is ridiculous, they know that I'm just a foreigner and that I can't speak Korean well", but then, through time I've learned that it might not be a big deal to me but to them it's a matter of respect and dignity. Once I started seeing things from their perspective, I became much more careful. Sometimes as foreigners we should follow the old adage, "When in Rome...