godan verb (-ku), transitive verb
explain; expound; preach; advocate
Used for setting out a doctrine, theory, principle, moral lesson, or viewpoint in words. More formal and weighty than ordinary 説明する, and often appears with 教え, 理論, 必要性, 重要性, or ideals such as 平和.
僧侶は村人に仏の教えを説いた。
The monk preached the Buddha's teachings to the villagers.
彼女は講演で環境保護の必要性を説いた。
In her lecture, she advocated the need for environmental protection.
godan verb (-ku), transitive verb
persuade; reason with; urge someone to do something
Means to persuade someone by explaining reasons or appealing to their judgment. It is somewhat formal or literary; in everyday speech, 説得する is often the plainer choice.
友人を説いて、計画に協力してもらった。
I persuaded my friend to help with the plan.
父は弟を説いて、謝りに行かせた。
My father reasoned with my younger brother and made him go apologize.