Follow the Crows
Planetouched are mortal creatures whose lineages trace back to outsiders, including celestials, fiends and elementals. Outsiders who can reproduce tend to be inter-fertile, therefore being able to mate with just about any other creature they desire. If the offspring of these unusual unions proves to be itself fertile, within a few generations planetouched will be born.
The planetouched races are:
5E proposes a language called Primordial, Greyhawk holds with earlier editions and uses the older elemental languages.
Air Genasi speak, read, and write Auran.
Earth Genasi speak, read, and write Terran.
Fire Genasi speak, read, and write Ignan.
water Genasi speak, read, and write Aquan.