I am from Guangzhou (Guangdong province), which is also known as Canton in English. I immigrated to Canada when I was about only 5 years old. Within that five years in China, however, I was lucky to be living in a place where school was taught bilingually in both Mandarin and Cantonese. Since my parents are not from Guangzhou, they speak Mandarin at home with me all the time (but they've learned how to speak Cantonese from all the time living at Guangzhou). Within these five years, I grew up juggling both Mandarin and Cantonese, but I must say that my Mandarin is stronger than my Cantonese. At school, I would actually talk to my classmates in Mandarin and some would respond to me in Cantonese. It really isn't hard to learn both of these languages; all you really need to do is get accustomed to the different pronunciations and sometimes different phrases used in Cantonese. If you were to only learn one of the two languages, it would have to be Mandarin as it is the main language used by China (and Taiwan) and it is used by the majority of the Chinese population. If you have the dedication and time, I would suggest you to expand your Chinese to both Mandarin and Cantonese, as many Chinese immigrants in other countries such as USA, Canada, and the UK are from Hong Kong or southern China. If you have any more questions, please feel free to ask! ^^