입이 가벼워요.

The Korean phrase '입이 가벼워요' (ipi gabyo-woyo) literally translates to 'mouth is light.' This idiom is used to describe someone who is prone to revealing secrets easily, or who cannot keep a secret. The '입' (ip) means 'mouth,' and '가벼워요' (gabyo-woyo) is the polite present tense form of the adjective '가볍다' (gabyopda), meaning 'to be light.' The origin of this idiom can be understood metaphorically. A 'light' mouth suggests that words or secrets do not stay contained within it, but rather escape easily, much like a lightweight object is easily carried or moved. Conversely, the phrase '입이 무거워요' (ipi mugeo-woyo), meaning 'mouth is heavy,' describes someone who is good at keeping secrets. In this context, a 'heavy' mouth implies that words are held securely and do not escape readily. This linguistic contrast highlights the intuitive understanding that lightness is associated with ease of movement or release, while heaviness is associated with resistance or retention. This idiom has been a part of the Korean language for a considerable time, reflecting a cultural understanding of discretion and the importance of keeping secrets. It's a common and easily understood expression in everyday conversation.