Taking shoes off inside the house.

 in Corea, shoes are never worn in the home, restaurants where patrons sit on the floor, Korean motel and even in some offices. In offices and motels, slippers are provided instead.

 Americans who have just arrived in Corea often just walk in wearing their shoes, giving no thought to the consternation they are causing their host.

Bump into others in a crowd

 Korean cities are overcrowded and people do, at times, bump into one another. Koreans think that this is inevitable and no one seems to mind at all unless the contact hurts.

Sitting on a table or desk when lecturing

 In Americans schools, this relaxed posture shows that the teacher and the students enjoy an informal, friendly relationship. in Corea, a teacher's social position is much higher than that of the students, and consequently Koreans generally feel that classroom is not a place fro informality. Likewise, this kind of informality is common in many American business during presentations but Korean workers find it uncomfortable.

Blowing their noses loudly in public

 It is common for Americans to blow noses louldy in public. But this is extremely disgusting to Koreans, especially if done during a meal. Most Koreans would rarely do this in public.

Calling people (especially elders) by their first names

 To build a trusting and cooperative friendship, many Americans will insist on using first names in business and social situations. This is disrespectful in Corea and Koreans consequently find it hard to do so unless they are close friends. At work, Koreans normally use a person's job title, followed by the family name ( For example, 'Manager Jeong' or 'President Kim') or use 'Mister' or 'Miss' in front of the family name. Koreans never call elderly person by his first name.

Saying 'Excuse me.' or 'I'm sorry.'

 Koreans are not accustomed to revealing their feelings to others. They rely on facial expressions to convey their feelings. For example, if a Korean happen to step on an American's foot in a crowded subway, he will try to apologize with his eyes. Nodding his head might be a way a Korean expresses his excuse. The American who doesn't understand the Korean custom will feel offended at that time. (In that case, Americans appologize by saying 'excuse me.' or 'I'm sorry.')