Itzli can't read or write modern languages. (Nor a few of the older ones, but that's only because he never had the chance to learn).

He claims they're too hard to leave and don't make sense. But in reality, deep down and somewhat hidden from himself, it stems from him not being able to let go of his olden ways.

(He is trying to learn a few now (namely English and French), though with a good bit of difficulty.)

He absolutely refuses to learn Spanish.