The trade language of Iralas, Common is spoken all over Iralas.
In practice, 'Common' is a 'jack of all trades' of languages; it allows for universal communication, but not much more than that.
Advanced topics such as academics or arcana usually use languages that allow for more deliberate expression.
Common has a few notable dialects. Speakers of different dialects can generally understand each other, but some words might be unique to a certain region or country.