Garder son calme est une sorte de vertu.
It's a kind of virtue to keep one's temper.
Il passe son temps à prôner ses vertus.
He spends all his time extolling her virtues.
De la nécessité, on doit faire une vertu.
One must make a virtue of necessity.
FrenchTextbook teaches rules like this, in a full beginner course.
162 lessons, 4,000+ exercises, and 6+ hours of audio.