to make (someone) understand (a fault, mistake, etc.); to reason with; to advise; to try to persuade; to exhort; to admonish; to warn (against doing)
母が弟を優しい声で諭した。
My mother admonished my younger brother in a gentle voice.
先生が生徒に礼儀の大切さを諭す。
The teacher counsels the students on why manners matter.
何度も諭しているのに言うことを聞かない。
Despite being admonished many times, they won't listen.