一を聞いて十を知る (Ichi o kiite jū o shiru)

Meaning: Said of someone so clever they grasp everything from a hint.

Literally: Hear one, understand ten

Example: “彼女は説明を少し聞いただけで全部理解した。一を聞いて十を知るだね。” — She understood everything after a short explanation: a word to the wise is enough.

Equivalents in English, French, Spanish, Italian, Portuguese, and 2 more languages

English: A word is enough to the wise.
French: À bon entendeur, demi-mot (literally: To a good listener, half a word)
Spanish: A buen entendedor, pocas palabras bastan (literally: For a good understander, few words suffice)
Italian: A buon intenditor poche parole (literally: For a good listener, few words)
Portuguese: A bom entendedor, meia palavra basta (literally: For a good listener, half a word is enough)
Dutch: Een goed verstaander heeft maar een half woord nodig (literally: A good listener needs only half a word)
Polish: Mądrej głowie dość dwie słowie (literally: Two words are enough for a wise head)