Common
Common, also referred to as Commonspeech or Common Tongue, was the trade language of Faerûn. Almost every sentient, civilized being spoke a smattering of it, and most were fluent. While most could not read or write the language, generally, the people of Faerûn were able to converse with each other in this language. The people of the continent of Zakhara referred to Common as Thorasta.
Description
Common was little more than a trade language; that is, it was not useful for complicated topics. It was simple and not very expressive as a language.
Speakers
Nearly everyone on the surface of Faerûn spoke Common as a second language, including non-humans. Those in remote areas spoke it badly, but most could get by.
Dialects
Dialects varied from region to region but communication was generally possible. There were literally thousands of these local dialects. Calant was a melodious dialect spoken on the Sword Coast, while Kouroo was a Chultan variant, and Skaevrym was spoken in Sossal. Another regional variant was Thorasta, which was spoken in the Western Heartlands, from Way Inn in the north to Beregost in the south, and from Baldur's Gate in the west to Hill's Edge in the east. Thorasta itself had dialects: Baldurian (used in Baldur's Gate), Reaching (around the Reaching Woods), a Backlands/Prairie creole, and High Moor (used by barbarian clans of the High Moor, so thickly accented it was sometimes mistakenly thought to be a separate language).
In other realms, "Common" could be altogether different; these were not in fact dialects but different languages. An example was in the Underdark, as the residents there spoke what was known as Undercommon.
History
According to Faerûnian linguists, Common developed directly from Thorass, or "Old Common", which was itself a pidgin variant of the Jhaamdathan language ("Old Chondathan") and Alzhedo. Among living languages, Common was most closely related to Chondathan.
Common was grouped with the Central Thorass languages in the Thorass language group.
Writing System
Common used the Thorass alphabet. Elves sometimes wrote Common in Espruar.

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