不能不 (bù néng bù) means “have to; cannot but”. It is an HSK 5 Chinese word in the HSK 3.0 vocabulary.
Practice each character:
我不能不告诉你真相。
Wǒ bùnéngbù gàosu nǐ zhēnxiàng.
I have to tell you the truth.
Updated: 2026-07-18