First, some background. When my engineer dad accepted an overseas position at its Italian subsidiary in rural NC - that is, when we moved to the U.S. - it was August 15. I was 15 years old. The only language I had studied in Italy was French. I had no knowledge of English except for what I had learned via Duran Duran and Beatles songs. High school in that part of NC began at the end of August. My younger sister and I were both placed (via math and other placement tests) a year ahead of our peers. Thus, I began U.S. high school as a junior (when by age I should have been a sophomore).
At the time, ESL classes were non-existent at my rural high school. Therefore, I was thrust into an environment where, in order to survive and at a bare minimum function in society, I was forced (for lack of a better term) to learn the local version of English (with a deep southern twang). My first few months are a blur to me - I can barely recall a few details.
But soon thereafter, between the classes and eventually the friendships I made, it became very easy for me to function and even succeed. I ended up graduating at 17, taking AP English in my senior year and becoming an accomplished writer. I also ended up majoring in technical writing in college and my writing skills are considered to be well above average by my employers and peers, considering I am in the legal and HR fields. I speak English as fluently as a native, although you can still detect an accent. Most people think I am German or Dutch, probably because my native Italian has a distinctive northern Italian pronunciation and inflection. I still have a hint of southerness as well.
Now, going back to Boojatta's question, no matter how well or poorly one speaks English, deportation will not be avoided simply because of one's language abilities.
I think at a minimum some basic English is necessary for daily life - even in communities where English is not the primary language. In my opinion, insulating yourself within a community that shares your culture and language is not necessarily a prescription for success. In other words, I am glad I didn't end up in an Italian-speaking community. I didn't lose my Italian identity or language. Far from it, infact.
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