Ah. That's a shame your world don't got it. Common Tongue is what almost any breed of monster speaks, from sea monsters to poltergeists, so long as they're more person than animal. A bit tricky to master, but worth it, even though most hunters don't bother, which is a shame. I've probably saved twice as many lives since I got it down.

[It had taken Dan several years and serious effort to get fluent, on account of Common Tongue being tonal, sharing no root words with human languages, being highly metaphor-based and lacking fun little things like adjectives. But the rewards have been immense, and Dan's endlessly grateful to his werewolf friends who invested the time in teaching him.]

If you'd like, I might could learn you some. I'm sure you'd pick it up quicker than I did.