Common

Common is the trade language of Faerûn. Almost every sentient civilized being speaks a smattering of it, and most are fluent. While most cannot read or write the language, generally, the people of Faerûn will be able to converse with each other in this language.

Dialects
Dialects vary from region to region, but generally, communication should be possible. Calant is a melodious dialect spoken on the Sword Coast, while Kouroo is a Chultan variant, and Skaevrym is spoken in Sossal.

In other realms, "Common" may be a different form altogether; these are not in fact dialects but different languages. An example is in the Underdark, as the residents there speak what is known as Undercommon. Inhabitants of different planes might also speak different forms of "Common".

Limitations and Advantages
The obvious advantage to Common is that practically every sentient creature can speak it. Even in remote areas of Faerûn like Murghôm, Samarach, and the Great Glacier, the inhabitants can speak at least enough of it to make themselves understood with a little creative pantomiming. Admittedly regional accents have a tendency to confuse the issue; natives of distant areas may regard each others' accents as strange or silly, but they can still understand each other.

However, it also has its disadvantages; not every concept can be easily related to others. Nuances of speech, names, and phrases can be expressed easier in older languages such as Illuskan and Dwarven.

History and Alphabet
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 is most closely related to Chondathan.

Common uses the Thorass alphabet.