[quote=@Raijinslayer]
Question: What's the most Common language in the Hundred Kingdoms?
[/quote]

Considering its position as something of a border region between the Scavenger Lands and "the East", I imagine it'd be a pretty even split between Riverspeak and Forest-tongue (dependent on whichever side of the area you're on, of course), with some smatterings of the various Realm languages thanks to Greyfalls and the efforts of any Immaculate Monks in the area.

[s]But it's not my game so don't take my word for gospel.[/s] ¯\_(ツ)_/¯

EDIT:

[quote=@Kirah]
Also just found someone saying gwyns home town has a different language than sky tongue and rip me if that is so. Anyway I'm going to sleep.
[/quote]

I'm like 95% certain that, as a city in the North, Gethamane's main language is Skytongue.