Dragon tongue

Dragon tongue, or sometimes, dragontongue, is the language that the dragon race of Durn speaks. All dragon riders have the ability to speak dragon tongue immediatly after they are joined to their dragon. Some spellcasters have this ability, even without being dragon riders, but it is exceeding rare for mortal spellcasters to be fluent in dragon tongue unless they are dragon riders. 
Some notable exceptions include:
Haluk
Ionela Fairhair
All elves can converse easily with dragons, as they can with any other animal. The spellcaster Abayomi and Aboline both could speak limited dragon tongue.