It is no wonder that the importance of English is growing increasingly in every aspects of society. I think it is necessary to recognize the cultural and behavioral grounds as well as the English language alone. Korea has been undergoing profound, radical changes and now many cultural elements are mixed and absorbed into the other cultures, particularly that of America. We have many more chances to face the Americans than before, and the behavioral collision between the two is bound to happen.

Koreans find it upsetting or peculiar when Americans beckon someone using the index finger. Koreans use their index finger only when beckoning animals not a person.

There are many other cases.

• Americans put their feet up on a desk or chair in an office to relax. It is common way for them but in Korea it's regarded as impolite because it shows a lack of respect.
• Koreans consider it bad form to pour one's own drink unless he/she is alone. We usually pour for others first, who will in turn pour for us. Especially when the other person is older, we do it with two hands.
• For americans, meal time is also a time for socializing, so they try to talk and communicate with others. On the other hand, we are taught not to talk much while eating.

Now let's look at the opposite situation, the case when Americans find it weird or upsetting from Koreans' behavior.

• Many Koreans are not accustomed to using the verbal expression "excuse me" or "I'm sorry". Rather they rely on facial expression to convey their feelings. Therefore many Americans who are newcomer in Korea think that Koreans are very rude.
• Another example is also linked to common manners. In Korea people don't generally hold the door for the person behind them. They are not used to holding the door if the person behind is a stranger.

• Some Koreans, especially women often touch or pat a total stranger's child. It simply means that they think the child is cute. Although accepted by Koreans as harmless and even complimentary, it may be cause for concern by an American parent. 

There are many other situations in which the two cultures are collided untouched.

I didn't mean to find fault with other cultures. And, of course, the cases I mentioned may not apply to all the people. I just wanted to show the usual differences between the two countries and hope for us to understand that with generous mind.