Using their middle finger to point

 Sticking out the middle finger is an obscene gesture in the U.S. and is only used as a strong insult. Most Koreans are not aware of its meaning and may casually use the middle finger to point or point out. (Koreans make use of obscene gestures by thrusting his thumb out of index and middle fingers.

Women covert their mouths when they laugh

 This common gesture is viewed by Koreans as a sign of good breeding. So, a polite Korean woman should not laugh loudly and openly.

 Unfortunately, Americans encountering this behavior would most likely feel that the woman is laughing at them while trying to hide her amusement.

Holding the door for the person behind them

 Americans expect people to hold the door for those behind even if they don't know. Most Koreans are not accustomed to doing this if the person behind is a stranger. They would, however, hold the door for their relatives, friends or guests.

Grabbing at someone's clothes to get their attention

 It's common for Koreans to touch or grab your sleeve to get your attention, instead of saying "Excuse me." This is irritating to most Americans and is normally considered to be very rude.

Making the sound 'Uh-huh' when a superior is speaking

 In the U.S., people often utter thd sound to indicate that they are listening during a conversation.

 But in Corea, it is similar to the sound used when a superior is listening to a surbodinate. Therefore, you should be careful not to make these sounds when you respond to older Koreans.

Putting one's feet up on a desk or chair in an office

 This is a common way for Americans to relax. But this is a very impolite in a Korean office; it shows a lack of respect.

Sitting with legs crossed in front of a superior

 Although it is simply a comfortable way to sit in the U.S., in Corea, this casual style of sitting is not considered polite when in the presence of a superior or an elder. It is especially inappropriate for women to cross legs at the ankles when sitting.

Crossing arms when talking

 To Americans, this is a casual posture which simply indicates that the person is considering something carefully. But in Corea it more often conveys sternness or disapproval toward toward the other person.

Standing up when a superior comes in.

 Koreans, who have been traditionally influenced by Confucianism, regard it important to show respect to their superiors or elders. When a superior enters the office, Koreans workers usually stand up to show respect. Americans, ont the other hand, raised in a more egalitarian culture, will say that showing respect is less important than doing their work.

in Corea, people generally dress in accordance with their age.

 Young women may wear bright clothing, for instance, while older women will usually wear conservative clothing in muted colors.

 American thinking is that you are only as old as you feel, so older people often wear casual clothing in a wide variety of styles and colors.

Cleaning ears in public

 While many Koreans do not think it objectable to clean their ears in public, most Americans think it should only be done in private.

Sucking air between their teeth

 This hissing sound is sometimes heard in response to a question. Americans may interpret it as meaning "Oh, no!" and feel that their simple request has caused a serious problem. in Corea, however, it is often used to indicate hesitation, somewhat like the English "Uh...", or "Let's see...", showing that the person is thingking of how to respond.