知らず

親の心子知（おやのこころこし）らず。

It is a wise father that knows his own child.

一文惜（いちもんお）しみの百（ひゃく）知（し）らず。

Penny wise, pound foolish.

りんご一日（いちにち）一個（いっこ）で医者（いしゃ）知（し）らず。

An apple a day keeps the doctor away.

そこ知（し）らずの相場（そうば）だ。

The bottom has fallen out of the market.

彼女（かのじょ）は怖いもの知（こわいものし）らずなの。

She is not afraid of anything.