> There is a negator word 不 bù, but just answering 「不」 wouldn’t make sense. That goes a bit too far. It would certainly be understood, but be considered quirky

> There is a negator word 不 bù, but just answering 「不」 wouldn’t make sense. That goes a bit too far. It would certainly be understood, but be considered quirky, or an indication that you're not a native speaker. My kids are bilingual German/Mandarin, and use it like that quite a bit.