Dialects, a way to distinguish people from different regeions, are not proper in public places at all. , for it causes emotional split between locals and foreigners. This is not good for social harmony which wishes every individual embraces each other. Such cases happen in cosmopolitans like Shanghai more often than not. Shanghainese is so proud of their language that they sometimes turn from madarin to dialect without concious, leaving the foreign audience deaf. Even though others endeavor to integrate themselves in the atmosphere, they are barriered by the language. The emotional split is just one of the adversy of dialect. It can also debase a person. Imagine a person with accent entering a private company. His/Her accent will no doubt stand out among madarin-speaking colleagues. Dialects show the statues of a person just like the movie TeaGirl. It makes the first impression.