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Jyutping bat1 dak1 ji4 zi1
Pinyin bù dé ér zhī

Definitions (CC-CEDICT)
  1. unknown
  2. unable to find out
Definitions (粵典–words.hk)
  1. 語句
    冇​辦法​知道
    unable to find out; unknown
    • 至於佢點解會喺日本就不得而知嘞。
      至于佢点解会喺日本就不得而知嘞。
      zi3 jyu1 keoi5 dim2 gaai2 wui5 hai2 jat6 bun2 zau6 bat1 dak1 ji4 zi1 laak3.
      The reason why he's in Japan is anybody's guess.
Definitions (Wiktionary)
  1. phrase, idiomatic
    to be unable to know or find out; to remain unknown; to be unable to ascertain
Definitions (Kaifangcidian)
  1. (沒有對應漢語詞彙)
Definitions (HSK3.0)
  1. HSK3 七一九级词汇表 #271
Examples (Tatoeba—Mandarin-English)
  1. Mandarin
    这个计划能否成功还不得而知。
    這個計劃能否成功還不得而知。
    zhè ge jì huà néng fǒu chéng gōng hái bù dé ér zhī 。
    • It is yet to be seen whether this plan will succeed or not.
  2. Mandarin
    当然,那些热水瓶是不是他们自己的就不得而知了。
    當然,那些熱水瓶是不是他們自己的就不得而知了。
    dāng rán , nà xiē rè shuǐ píng shì bù shì tā men zì jǐ de jiù bù dé ér zhī le 。
    • Obviously, we don't know if those thermos flasks are their own.
Examples (粵典–words.hk)
  1. Cantonese
    至于佢点解会喺日本就不得而知嘞。
    至於佢點解會喺日本就不得而知嘞。
    zi3 jyu1 keoi5 dim2 gaai2 wui5 hai2 jat6 bun2 zau6 bat1 dak1 ji4 zi1 laak3.
    • The reason why he's in Japan is anybody's guess.