Using dialects in formal settings does not necessarily mean unprofessionalism, it depends on the specific context and background. In some formal occasions, such as national conferences, cross-regional business talks, or formal academic reports, the use of Mandarin (or the standard language) is usually considered more professional because it helps to ensure that all participants can clearly understand. But in some cases, the use of dialects may be appropriate or even necessary： -When all participants speak the same dialect -At specific local events or regional meetings -In order to enhance communication and trust with the local people -Demonstrate language diversity in some cultural or artistic performances Language ability and professional literacy are independent of each other. A person can be proficient in dialects and can also use standard languages when needed, demonstrating a high degree of professional quality.