Due to their time in captivity, Jerome and Shorty have developed some very non-frog tastes in edibles. Find them some of their favorite foods and they will teach you the Froak language!
All of the food is in Omen's Call in Fens of Nathsar.
In addition to the language, Shorty follows you around for a while. He is quite annoying, but zoning or camping to yourself (or at worst, jump your character off a cliff and die) should get rid of him!