不知好歹 bù zhī hǎo dǎi

DEFINITIONS

  1. unable to differentiate good from bad (idiom)
  2. not to know what's good for one
  3. unable to recognize others' good intentions

CHARACTERS

不 bù
HSK 1
no, not; un-; negative prefix
知 zhī
HSK 2
know, perceive, comprehend
好 hǎo
HSK 1
good, excellent, fine; well
歹 dǎi
HSK 6
bad, vicious, depraved, wicked