One thing you may notice if you ever visit Korea is that many buildings do not have a fourth floor. Much like the number 13 in the USA, the number 4 is really unpopular here. Korea has two sets of numbers. One, which my dad would remember from Tae Kwon Do days, is the pure Korean number set, namely hana, dul, set, net, and so forth. The other set, derived from Chinese, is used for numbers larger than 100 and also for the minutes in telling time. The pure Korean set is used for the hours and for other things, such as kimchi jjigae han juseyo (“give me one bowl of kimchi jjigae”).
The number four in the Sino-Korean number set is pronounced sa. 四 is the Chinese character for the number four. However, it has a lot of other meanings, such as temple 寺 (佛國寺 or Bulguksa is a UNESCO World Heritage temple in Gyeongju) or death 死. You see this character in warnings such as “依據中華民國刑法，販賣、運送毒品者可判處死刑” or “Drug trafficking is punishable by death according to the criminal laws of the Republic of China”. Therefore, instead of a fourth floor, many buildings simply skip it or mark it as F. When I was in Gwangju and had to take the elevator to the fourth floor, it would say, “에프 층 입니다” or “This is floor F”.
The Chosun Ilbo recently ran a story on the Chinese superstitions involving numbers. The Chinese don’t like the number 4 any more than the Koreans do. The government of the Hong Kong Special Administrative Region has made a fortune by auctioning off license plates with lucky numbers. You can read that story here.
There is one industry in Korea which does not fear the number four. As you might guess, it is the funeral industry. There are several funeral homes, such as this one in Daegu which proudly uses (080) 425-4444.