My thesis will, afterwards, be devoted to this issue of code switching to find out more about the nature of this phenomenon defined by scholars and sociolinguists. Firstly, I will raise the issue of bilingualism and I will also take time to compare code switching with two similar linguistic concepts, code mixing and borrowing. Secondly, I will list the main types and some pragmatic aspects of switching. In the rest of the paper I will present Hungarian immigrants living in three foreign countries, United States of America, Canada and Australia and collect actual speech samples from them as evidence to prove the reality of language shift.