不得而知
bù dé ér zhī · HSK 7
unable to find out
🤷 not-get-and-know: you cant get it, so you cant know it
Each character spells out the frustration: 不 (not) 得 (able to get) 而 (and so) 知 (know). If you cannot obtain the facts, knowledge stays out of reach — a four-part logical chain ending in a shrug.
不 — single pictograph; bird flying upward
Originally a pictograph in oracle bone script, traditionally interpreted as a bird flying up toward the sky and unable to come down, suggesting negation or refusal. Over time it became the standard negation word in Chinese, used before verbs and adjectives to mean 'not'.
得 — 彳 (step) + 旦 (sun/day) + 寸 (hand)
Originally depicted a hand 寸 reaching for a cowrie shell 貝 (later simplified to 旦), with 彳 'step' added to show going out and obtaining something. The core meaning is 'to get' or 'obtain'. The reading děi extends this to 'must/have to' — what one is obliged to get done.
而 — pictograph of beard/whiskers hanging from chin
Originally a pictograph of a beard or facial hair hanging below the chin, visible clearly in oracle bone and bronze script forms. The beard meaning was lost early, and the character was borrowed phonetically to write the grammatical conjunction 'and/but/yet'. This connective use has been standard since classical Chinese.