the penny drops
US /ðə ˈpɛni drɑps/
UK /ðə ˈpɛni drɑps/
1.
恍然大悟, 終於明白
used to say that someone has finally understood something, especially after a period of not understanding
:
•
It took him a while, but then the penny dropped and he realized his mistake.
他花了一段時間，但後來他終於明白了，並意識到自己的錯誤。
•
I kept explaining, but it wasn't until I drew a diagram that the penny dropped.
我一直在解釋，但直到我畫了圖表，他才恍然大悟。