never come across a spirit that speaks in spirit language. have come across an illiterate one, and i've met my share who love messing with people while using a ouija board by spelling gibberish. i've asked a couple spirit friends about other languages, never come across spirit though as an answer, normally they speak English, but i've met quite a few who also speak french [grew up in quebec] and a couple who spoke German, but none speaking spirit.
same goes for dragons who speak 'dragon'. yes, there is a language of dragons, but most whom i encounter either don't speak to me, say one work, or ask me a riddle. had a dragon write in runes once, that's the closest i've come to encountering any being speaking an unknown dialect.