Languages are treated unlike 3.5 or AD&D 1st Ed. The Dwarves are both veterans of Goblin wars and have some goblin but goblins speak many different dialects and even languages and use a corrupt, base dialect of Westron to communicate. Most goblins know some Westron.
Gil-Gandel knows most of the local (western) goblin languages and dialects as a bard. Miron knows some, mostly those of Mordor. Bitur is actually reasonably familiar with the local Goblin Gate and Gundabad variants but not Moria. Gwaelur is stronger with some Mordor variants and Moria.
The Hobbits and Humans know none. Not even Brin.