godan verb (-su), transitive verb
express properly; explain well; articulate skillfully
Implies speaking or writing with clarity and skill, often in a way that persuades or conveys complex ideas effectively.
彼は難しい概念をわかりやすく言いこなした。
He articulated the difficult concept in an easy-to-understand way.
自分の考えをうまく言いこなせなくて
I'm frustrated that I can't express my thoughts well.