why is there no 4th floor in hospitals
Tetraphobia The Chinese word for four (四, pinyin: sì, jyutping: sei3), sounds quite similar to the word for death (死, pinyin: sǐ, jyutping: sei2), in many varieties of Chinese. Similarly, the Sino-Japanese, Sino-Korean, and Sino-Vietnamese words for four, shi (し, Japanese), and sa (사, Korean), sound similar or identical to death in each language (see Korean numerals, Japanese numerals, Vietnamese numerals). Tetraphobia is known to occur in Korea and Japan since the two words sound indentical, but not at all in Vietnam because they carry different tones (in the case of the word for "four", whether it's the Sino-Vietnamese reading tứ or the more common non-Sino-Vietnamese reading tư, neither sounds like the word for "death" which is tử), and Vietnamese does not use Sino-Vietnamese numerals as often in the first place.