UNTIL I GET CONFIRMATION FROM BLIZZARD we don't know what languages omnics can speak besides the global languages of BeepBoop and English, I'm headcanoning that he can speak the top 4 most common languages on Earth, (so English, Mandarin, Spanish, Hindi), along with Nepali because that's where he's lived for most of his life. He probably knows a few phrases in Japanese from Genji, but I felt like going "oh he knows every human language" would be like, too much lol