Hyman Kaplan

I more the read the book the more I started to feel like Kaplan was making fun of America and the way that it was structured during that time period.  In the book, Mr. Parkhill wonders several times if Kaplan wasn't some kind of genius, and I think that he was exactly that.  He is almost too smart and observant to learn English properly because points that he makes actually make sense, just not within the rules of America.  From the book, I get the impression that he has a better idea of what the rules are than he's letting on but at the same time I could be wrong.  I think the funniest example of this is the discussion with the substitute about "a so-and-so" vs. "so-and-so."  Kaplan deliberately makes the substitute explain "a so-and-so" and then uses "so-and-so" in his explanation of the context.  It's also fitting that he plays this game with someone who isn't used to his ways.  I think the mentioning of his endless smile paired with the last line of the book shows just how much Kaplan was enjoying himself.  The word that comes to mind to describe Kaplan is really informal, but he basically seems like he's trolling his teacher and his classmates.  I really liked this book!

So I guess my question is, do you think a lot of immigrants pretended to be less knowledgeable of American ways?  If so, why?