I had English speaking only rule while I was in the Army. It was to speak only English while I was in the workplace. Technically the military is a 24/7 job. If I took them literally I wouldn't speak spanish (which is my first language) even at home and when I was on my "break". I wouldn't know how to relate to the matter in the civilian world. If anything if your employer allows a loophole and bends the rules more power to you. If not suck it up and drive on it's not personal it's about professionalism in the workplace. This comming from a Puerto Rican born in CT USA that spoke only spanish till I started Kindergarden.