Those who follow will (most likely) be educated in our language..
Are you making it illegal to be a citizen if you are illiterate?
There is a proficiency level mandated for becoming a citizen, and a test one must pass in order to be naturalized, that needs to remain in English. There are also State laws regarding the ability to to read and/or recognize road signs in order to obtain a driving license.
Looks like we have all the laws we need already in place.
IF a State opts to issue driving tests in a language other than English, that is a matter for the people of that State to address, it isn't a Federal issue at all.