The concept of "formal" may have different meanings in different occasions and cultural backgrounds, and it does not necessarily mean that dialects themselves are informal or immature. The following points can help understand this issue: 1. Functional division of language: Standard language is often widely used in education, media, administration and formal writing because it is uniform and easy to understand in extensive communication. In contrast, dialects reflect more local characteristics and spoken expressions in daily life. Therefore, in the traditional sense, "formal" is often tied to standard language. 2. Contextual issues: In specific social, cultural or artistic occasions, dialects are sometimes more infectious and unique than standard languages. In some literary works, dramas and folk arts, dialects can better convey regional culture and emotional colors. Therefore, in these contexts, dialects appear to be more vivid and close to life. 3. Social evaluation and language power: People's views on "formal" and "informal" are often influenced by education, history and social values. The reason why standard language is considered "formal" is, on the one hand, because it has been "standardized" and on the other hand, because it occupies a dominant position in the power structure. In fact, all language variants, whether standard or dialect, are rule systems formed by language users through long-term practice and cultural inheritance. None of them is naturally "high-level" or "low-level". 4. Distinction between form and function: From a linguistic perspective, "formal" often refers to the standardization of the style of speech, such as the choice of vocabulary and sentence patterns. Although dialects have their own unique vocabulary and expressions, they can also adopt their standardized and "formal" forms in appropriate occasions, such as local government documents, cultural activities and even literary creation. In other words, the formality of a language is not determined by whether it is a "dialect", but by whether it meets the purpose of communication and the expectations of the audience in a specific context. In summary, dialects are not necessarily always considered less "formal" than standard languages. This concept reflects more the division of language form and use in society and the education system. In fact, each language variant has its own unique value and appropriate field of use. The key is whether they can meet the needs of communication.