Most monsters speak their own language. For the Golarion setting, there are the following human and non-human languages:
Azlanti, Common, Dtang, Dwarven, Erutaki, Goblin, Hallit, Hon-la, Hwan, Jistka, Kelish, Minatan, Minkaian, Orc, Osiriani, Osiriani-Ancient, Polyglot, Shadowtongue, Shoanti...