Dragon chatting with friends
Dragons communicate with eachother, as well as many other species, in more ways than you think.
The most common way a dragon communicates is verbaly, once it's mastered the art of speech in any of the dozens of human dialects, or hundreds of dragon ones. Almost every clan, cult, flight or gather of dragons has a different slang, and then there are many other basis languages for inter-clan communication, and clan-less dragons.
But Dragons are also big body talkers. The movements and expressions of a dragon can convey messages themselves, stirring, and responding to natural reactions. For instance, a Dragon can command you to sit down with a look, and you would understand. Don't worry, you'll know that look when you see it.
The lesser class of dragons are incapable of complex speech, and rely on body talk most of the time. The common natural sound of a dragon is a nice, hearty roar, which the lesser class expresses with great enthusiasm.
The Greater class dragons can also use telepathy to communicate with people, and can sometimes influence a beings mind in this way.