Following on my past linguistic posts (see Japanese Resources page for more of that), I’m going start periodically introducing fun words and phrases that you might like to use in Japanese. 一緒に勉強しよう！*
Kanji (rarely used in this case): 勿体無い
Meaning: Wasteful; Regret related to waste
もったいない is an interesting concept. Literally, it means a lack of the natural dignity of a thing. In modern Japan it’s used as either an exclamation or an adjective. It refers both to physical waste, such as throwing away something that can still be used, and to things like wasted talent, wasted effort, or even a mentality that leads to waste. From what I understand, it was kind of outdated for a while, but in recent years it’s become popular again.
もったいない！ –> What a waste!
捨てるのはもったいない/Suteru no ha mottainai –> It’s wasteful to throw it away.
This is a hard term to fully render in English, but you will definitely run into it if you spend some time in Japan and I think it’s fascinating. What about you?
*Let’s study together!