Education has nothing to do with their not speaking English. They have no motivation or desire to speak it . They have no desire to assimilate. You cannot force them to learn. It is not an education issue. And you want them to speak proper English? I bet the majority of them cannot even speak Proper Spanish.
I think we are speaking the same, just different on semantics.
One reason people refuse to assimilate is that there is a language barrier caused by not learning a language well enough to use it in ordinary communication. When we have the legal signs, the voting booth and lots of other things in languages other than English, they retire back to their 'comfortable language'.
Education of these people in basic civics taught in English, and the cessation of dual-language in our Society will entice or force these people to use English more and do what you wish them to do, assimilate.
Diversity is a bunch of crap, and never helped a Society to become better. It weakens them.