Common

Originally created as a trade language for use by the dwarves, elves, and humans, Common has grown to become the dominant language in many human societies. Many nations such as the kingdom of Valonde, The Holy Arbia Empire, Grand Duchy of Kharsyt and Drotalis. 
Given the fact that Common has taken the place of the various languages the humans once spoke different regions have different accents and sometimes slang combining Common and the original language. Below are the regions and their variations on Common. 
Valonde and the Iron Plains: The original language of the region is Kêkniyn and when they began to primarily use Common a few things carried over. The three main things that were carried over are : I is pronounced like ee when not by itself or influenced by other vowels (i.e. if becomes eef, important become eemportant and so on.  W is pronounced like V (similar to german but V stays the same as well) L is rolled and breathy (see DM for demonstration. I'm not a good enough linguist to write this out)
Noctirnan/ the Grand Duchy of Kharsyt: The original language of the continent is Dikteyian. (For their version of Common think of a Romanian speaking English with a heavy accent.