Are you asking to validate any pair of words that might be used as first and last names (so long as they don't contain special characters)?

If so, what shall we do about first names taken from the language in question, but not commonly considered "names?" "Charity" might be an english language edge case; what if I named my nextborn "Broccoli?"

And what do we do with the commonly accepted names in Spanish that do have accents -- I believe Jesús and María are common cases.

I offer this hypothesis despite the seemingly contrary second sentence, which might be understood to mean that you want only to deal with names of languages. But you might wish to clarify your question.