【詎期】的英文翻譯是 **"how could one expect"** 或 **"who would have thought"**。

這個表達常用于文言文或古詩詞中，表示驚訝或出乎意料，強調事情的發生超出預期。

例句：
- 詎期此事竟成真 → **How could one expect this to come true?**
- 詎期他今日成功 → **Who would have thought he would succeed today?**

根據具體語境，也可靈活譯為 **"unexpectedly"** 或 **"beyond expectation"**。