In Korean, the liquid was avoided in word-initial position until the late nineteenth century although it was used intervocalically and syllable-finally. Since Chinese vocabulary was imported around the eighth century, the Chinese lateral [l] in word-initial position was borrowed as [n]. This substitution is still strictly applied to Sino-Korean common words by orthographic regulation. However, since the late nineteenth century, the word-initial liquid has manifested itself in loanwords and Sino-Korean proper names. This talk aims to both confirm that a liquid is prohibited in native Korean and to suggest that adopting Chinese [l] as [n] is none other than a substitution of a native sound for a foreign one due to lack of an initial liquid and similarity between a flap and a nasal.