In South Korea, it's four. The reason behind the fear of the number four, known as tetraphobia, lies in the way it sounds. The Korean word for "four" sounds much like their word for "death." Some elevators in South Korea do not have the number 4.
In South Korea
The number 4 sounds like the hanja for "death" (사) (although Korean has no tones), so the floor number 4 or room number 4 is almost always skipped in hospitals, funeral halls, and similar public buildings.
But the number four is considered unlucky because it sounds a lot like the word for “death,” and as a result Chinese buildings often lack a fourth floor (just as American buildings sometimes skip the 13th). Likewise, Chinese drivers avoid license plates ending in four.
Traditionally, 4 is unlucky because it is sometimes pronounced shi, which is the word for death. Sometimes levels or rooms with 4 don't exist in hospitals or hotels. Particularly in the maternity section of a hospital, the room number 43 is avoided because it can literally mean "stillbirth".
Many Chinese people do not want the number FOUR in their house number or phone number. But: FOUR is a lucky number in Europe, North America and Australia. The FOUR-leaf clover is a symbol of luck.
Background: The numbers 4, 14 and 24 are associated with death for Cantonese-speaking Chinese people, as the words for these numbers sound like the words for "death", "must die" and "easy to die", respectively.
Examples of Korean superstitions
The number 4 is a symbol of bad luck. In elevators, the letter F indicates the fourth floor instead of the number 4.
Similar to many Asian cultures, specific numbers are said to be associated with luck and prosperity. In Korea, numbers like 8, 9, and 3 are often considered lucky.
Lucky number 3,7,8
If you are in Korea then add numbers 3, 7, and 8 to your lucky number inventory as these numbers determine many things. For example parents like to set weddings on any date with an '8' in it, or couples that have a 3 or 7 year difference are considered to be the best match.
Today, the number 13 is synonymous with misfortune. Subsequently, the concept of "unlucky number 13" entered the zeitgeist, and by 1910, the term triskaidekaphobia, which means "fear of the number 13," was coined by a pioneering psychologist, further perpetuating the superstition.
Tetraphobia is an irrational fear of the number four and it's common in a lot of east Asian countries like China and Japan. The reason is quite simple, really – in a lot of east Asian languages, the word for “four” sounds a lot like the word for “death”.
In Vietnam, 4 is generally seen as an unlucky number, while 6 and 8 are lucky numbers. The reason is their similar pronunciation to words like “death” (tứ/tử), “money” (lục/lộc) or “development” (bát/phát) in the old Sino-Vietnamese language.
They discovered salt kept food from going bad, and they started to believe salt could keep evil spirits away. Since then, people throw salt (or just say it) in order to push devils away after unwelcomed or despised people visit.
Apparently it's the number nine. It all started at the time of Korea's liberation from Japanese occupation, when there were eight shamans representing the eight provinces of Korea. Out of these, the strongest shaman was thought to be the one from Pyongan-do.
Although slightly less well-known, eight is also a lucky number. This is due to its shape – 八. Called suehirogari (末広がり), it's lucky because it widens at the bottom which reminds one of prosperity and growth. Japanese people tend to be quite superstitious and this is why lucky and unlucky numbers are important.
The numbers 8, 2, 6, and 9 are the favorite lucky numbers of most Chinese people. Combinations of the above are deemed as lucky numbers too, such as 66, 88, 168.
9: Just as the number four has a bad-luck soundalike in Chinese, 9 is feared in Japan because it sounds similar to the Japanese word for torture or suffering.
Koreans say “hwaiting” when they want to wish a person good luck or give someone encouragement. It can also be used to say “you can do it!”, “let's go!” or as a way to cheer someone on. Example: 항상 화이팅!
The number 4 (四, pinyin: sì; Cantonese Yale: sei) is considered an unlucky number in Chinese because it is nearly homophonous to the word "death" (死 pinyin: sǐ; Cantonese Yale: séi).
Naturally, people believe that some numbers bring luck, fortune, and wealth. 3 is one of the luckiest numbers according to Korean superstitions. First, many may be aware of the sacred meaning of the number “3” in Christianity. Korea is actually a very Christian country, and so many believe that it is a holy number.
The number 13 may be associated with some famous but undesirable dinner guests. In Norse mythology, the god Loki was 13th to arrive at a feast in Valhalla, where he tricked another attendee into killing the god Baldur. In Christianity, Judas — the apostle who betrayed Jesus — was the 13th guest at the Last Supper.
the pronunciation of 4 in Japanese is SHI which means death! That's why you never see room number 4 in hospitals and some hotels.
The number 8 is considered the luckiest of numbers in China and they believe the more 8's the better. The Cantonese word for eight, which is pronounced “ba”, sounds similar to the word which means “prosper” or “wealth”. In regional dialects the words for “eight” and “fortune” are also similar.
Number 4 natives are considered as lucky and fortunate. They enjoy a good social status. They are far-sighted and thrifty, thus setting up a good bank balance is not a big task for them.
No lifting
Unlike many other Asian countries, it's unusual to lift your soup or rice bowl while eating your meal in South Korea. Korean Dining Etiquette dictates that you should make sure that your soup or rice bowl is on the table throughout the meal and use your spoon to eat the rice instead of chopsticks.