This area of China is rich with ethnic minority groups. Each have their own languages and some have their own writing systems too.
Among the Han Chinese, these area is also liguistically very rich, with many mutually unintelligible "dialects " spoken. Cantonese is the largest non-Mandarin "dialect ", though it is not spoken everywhere, and there are also dialectal variations within Cantonese which can also be mutually unintelligible. Other "dialects " spoken include various belonging to the Min group, as well as Hakka. As Mandarin is the only language taught in all schools, most younger people would be bilingual in Mandarin and their local tongue. Written Chinese Hanzi script can be understood irrespective of the spoken language.