Have you ever shouted "Bravo!" at the end of a play or cooed "Good boy!" to the dog when he followed a command? Then you know how to commend someone — in other words, to express approval aloud.
The most common meaning of commend is "to compliment." You commend someone when you tell them "Well done!" You can even say "I commend you on your hard work." Back in the days of Charles Dickens, commend often meant to put (someone or something) in the hands of someone else for safekeeping. Case in point: David Copperfield was out of luck when his cruel stepdad commended him to the equally cruel schoolmaster Mr. Creakle at Salem house.