Languages Smaug spoke?

[Inziladun]

Originally Posted by Zigûr

It would be interesting to know if dragons had their own language. What language did the servants of Morgoth speak in the First Age? Presumably it was some corrupted version of Sindarin, Quenya (Morgoth appears to have spoken both of them) or perhaps of the Primitive Quendian spoken by the first Elves to become Orcs. I could imagine the Dragons of the North retaining vestiges of such language, as they appear to have been long-lived.

Aside from Sauron's relatively unsuccessful Black Speech, I can't recall an instance of the forces of evil in Arda acquiring a unique language.
I would agree that Morgoth probably would have used some debased Quenya or Sindarin for speech among his minions.