I think you could certainly justify him speaking some combination and varying degrees of French, German, Italian or Spanish, and maybe bad grammar school Latin. His family travelled a lot. But I don't think we have canon on any of it.

If it's Nix's PoV, then he's more or less worrying about Dick worrying himself to death, with a side order of What Does This Mean For Our Friendship? and a dash of What If He Is Really a Monster Now!? Which would probably play into the same plot, more or less, just with a different focus.