This will be make Kismet's posts pale in comparison. But, sorry YK, I really try to avoid these discussions... but....
I know many 2nd, 3rd, or even 7th generations of Americans that can't speak English very well. Some don't even have the excuse of not having a different language in the home.
In the words of the gentleman who owned the elementary school I attended: "if you intend to do business in, or become a leader in this community, you had better learn Spanish." This was in the 1950's southern California. At the time it was a mostly rural, agricultural community.
I have struggled with Spanish all my life, both its grammar and syntax are difficult for me... but I continue my education of same. I've studied Latin and German, remain conversant in German although I probably only speak 3 or 4 sentences a year with my F-I-L and a correspondent in Germany (who loves to practice his English on me). After two years of study I was able to think in German, thereby requiring no translation, except in the very difficult technical or theoretical discussions. However, after 52 years since my first introduction to Spanish I am rarely able to relate my thoughts in Spanish beyond the most rudimentary of exchanges. Some of that is directly related to the form of Spanish I learned, and the form as used by the masses. I strongly suspect that my problems with Spanish are shared by others, even to the extent that some Spanish speakers would share a reciprocal difficulty in English. Break thru some of the barrier with a little conversation, you'll find FEW Spanish speakers among our immigrant population that can read their own language. For those that can, land jobs and other advances in their own countries that preclude their need to come to Norte America. You'd be surprised at the number of Hispanics that are SHOCKED

when they notice the newspaper I'm reading in their factory's lunchroom is their own Spanish language periodical. They ask, "you can READ Spanish?" And upon inquiry, they admit, "not very well."
Wait; that same could be said of our own youth and the barely sufficient education they receive at the hands of public schools.
I'm currently reading two books.
John Adams by David McCullough and
Ciudad Juarez by Rafael Loret de Mola. In perspective, the English as used by John Adams and others of his era is nearly as difficult as the Spanish used by Mr. de Mola.
Quite frankly, had my parents known of this dogma by the owner of this private school, not to mention their denial of the existance of left-handers (there's a reason my left knuckles are larger than my right), I would have been denied the head-start I received. Little good that it's done me!
I can only suggest that you apply a little effort and learn some Spanish; you'll learn that they're not talking about you, not planning the immediate overthrow of our gov't for their own! Remember, their gov't did little to help them in their own countries.
It will also help you in your own job and career. For as that same school adminstrator (also the 5rd largest land owner in CA at the time), said, "how do expect to KNOW that your instructions are understood and will be carried out if you rely solely on the part of intepreters."
(Yes, I remember that lunch conversation very clearly, as he was quite impressive to a 6yo)!
However, I do agree that most gov't business should be conducted in English, for the simple fact that "empuje en la linea para salida" is not always translated correctly! Let alone more complex requirements.