Thorass language

Thorass, or Old (Auld) Common, was an old human language, the original trade language of Faerûn and the direct ancestor of Common.

Description
Thorass was similar enough to modern Common that it could be directly translated into the latter language, though it would have an jarring form and archaic vocabulary. It had a base 10 numbering system.

Speakers
By the second half of the 14th century DR, few were literate in Thorass, with some exceptions in the southern parts of Faerûn. For example, in Amn, as late as 1370 DR, all official business was still conducted in this archaic language. The dialects of Common used in court in Tethyr and Erlkazar had stronger influences from Thorass than elsewhere, and the city of Zazesspur maintained its own variety of the language as well. Like in Amn, business in Durpar was often conducted in Thorass.

Because the Shadovar who returned to Toril in 1372 DR were from an earlier time, some of them still spoke Thorass as a second language.

Script
An unknown scribe eventually developed a written alphabet for Thorass. While the language had almost fully died out from common use by the end of the 14th century, the alphabet survived and was used in languages such as Common, Chessentan, Rashemi, and Uluik.

History
Thorass was thousands of years older than Common, having come about because of trade along the Lake of Steam from the early Calishites and Jhaamdathans. It was thus derived from the ancient language of Jhaamdathan mixed with Alzhedo. There was also a great deal of evidence that Thorass was derived in part from older incarnations of Jotun, the language of giants.

It was classified as belonging to the Central Thorass subgroup of the Thorass group of Faerûnian languages. Because it was derived from Jhaamdathan, Thorass was a cousin of modern Chondathan, since Chondathan was directly descended from Jhaamdathan.