-From someone who's studying Mandarin in Thailand-
Mandarin
I am Cantonese and I usually don't understand what people are talking about when they speak in Mandarin. So the answer is no. You wouldn't be able to understand completely until you've learnt mandarin but you can sometimes make out what people are saying in mandarin. But if you do learn either of them, learning mandarin and already knowing Cantonese would make it easy to learn but it wouldn't be the case the other way round. This is probably because Cantonese has more tones and is harder?
It is because mandarin is not really easy to learn and it is not spoken by the majority of the population.
There are many sorts of Chinese around the world and even in Asia so, no, not every Chinese child will learn Mandarin. Some may learn Cantonese, Vietnamese, Thai, Malay, etc. Some for instance may even learn English (if they grow up in the US, Australia, UK, etc).
It is said that Mandarin Chinese is the most difficult language to learn after childhood, followed closely by English.
Mandarin
Chinese is not a language. You can learn Mandarin or Cantonese from tutor or the internet because the internet is just that amazing.
I am Cantonese and I usually don't understand what people are talking about when they speak in Mandarin. So the answer is no. You wouldn't be able to understand completely until you've learnt mandarin but you can sometimes make out what people are saying in mandarin. But if you do learn either of them, learning mandarin and already knowing Cantonese would make it easy to learn but it wouldn't be the case the other way round. This is probably because Cantonese has more tones and is harder?
Mandarin is one of several dialects of the Chinese language. So, if you learn Mandarin, your are learning Chinese.
It works the same as speaking any language. If you known Cantonese, you can speak it. You also take classes to learn it.
"Yes, there are many DVD movies available to purchase that help people learn the Mandarin language. Usually, to learn a language, you should also take actual classes from a person who is fluent in Mandarin."
It is because mandarin is not really easy to learn and it is not spoken by the majority of the population.
Probably Mandarin Chinese.
The most important language for the Chinese is Mandarin as this is the official dialect used in china. People tend to learn the local dialect/language used in their home town from their parents, and will talk in that at home. But once they start school they learn standard mandarin. Also in school they will learn English. Many Chinese learn English and see it as an important way of connecting with the west. That aside there is little interest in learning the other dialects in china, as people from different regions will converse in mandarin. However in the canton (guang dong) province, particularly Hong Kong and neighbouring areas there is a history of cantonese the local language. And many Chinese who work there choose to learn this. Plus lots of Chinese movies and music is in cantonese, giving it some social significance. Hope this puts things in perspective for you!
There are many sorts of Chinese around the world and even in Asia so, no, not every Chinese child will learn Mandarin. Some may learn Cantonese, Vietnamese, Thai, Malay, etc. Some for instance may even learn English (if they grow up in the US, Australia, UK, etc).
To learn the simplified version of the chinese mandarin language, one could take classes via Clear Chinese or Learn Chinese EZ. There is also the computer program Rosetta Stone, which is nationally known for being the easiest program to learn another language.
Don't be stupid, they speak Dutch. Um, DER! (But in all seriousness, cambodians speak cambodian. Although some may learn a second language of Cantonese.)