Mandarin Chinese is the official spoken Chinese language widely adopted throughout China, including Hong Kong. The same is adopted by Taiwan and Singapore. Cantonese is a dialect mainly spoken by Chinese in Hong Kong, Guangdong.Province and overseas Chinese communities. The pronunciations between Mandarin and Cantonese are totally different. There are no differences between the two as far as writing is concerned. In a nutshell, if you only know Cantonese you can communicate with 5% of the Chinese in the world and if you only know Mandarin you can communicate with 95% of the Chinese in the world. I note that you consider moving to Canada. I lived in Toronto before. The majority of the Chinese in Canada speak Cantonese as most of them were from Hong Kong.

There are two different languages withing the same language family (Sino Tibetian). Pronunciation is very different. Syntax is similar. You can compare it maybe like English and Dutch, which are also in the same root language group. If you speak one, it is easier to learn the other one. You can say, Mandarin is the most widely spoken Chinese language INSIDE China. Cantonese is the most widely spoken China language OUTSIDE China. Most overseas Chinese communities speak Cantonese. The writing is different too. Many mandarin expressions don't exist in Cantonese. If you want to learn writing then it is better to just learn it from Mandarin. Interestingly, not many people in China are Mandarin native speakers. Most speak it as 2nd or 3rd language. Less then 10% of people in the PRC speak Mandarin at home.

Hi Andrew! I am from northern China and I can‘t understand Cantonese at all, when a people speak Cantonese. I think it's pronunciation is quite different from Chinese Mandarin. And in Grammar and vocabulary there are also many differences between the two. Cantonese is more similar to the ancient Chinese.

I can speak both. People who know Cantonese don't necessary understand Mandarin and vice versa. Generally the writing is almost the same, but the way to pronounce the words is different. Hong Kong people speaks Cantonese, People in beijing, China usually speaks Mandarin. The open and closing ceremony of the 2008 Olympic games in Beijing was bilingual - English and Mandarin. TV show and Drama series from Hong Kong are in Cantonese. Make use of the youtube and you will know the differences.

With respect to VL, regarding the writings, there is not the difference between Mandarin or Cantonese, that is the difference between simplified or traditional Chinese characters. With regard to Toronto, I think it depends on whether you are talking about Greater Toronto or Metro Toronto.