Common
Common is the language spoken by the Mennesker. It was originally a dialect of Dwarven, but obtained a very large number of loan words due to the trade routes that the Folketen maintained. As such, it is the most frequently used mercantile language to assist in international trade agreements.
As a result of its widespread use and origin in a culture focused on geology and metallurgy, many other languages borrow words from Common to describe rare metals and complex alloys.