Question: do all chinese dialects use the same characters

Answer: Yes, Chinese languages and dialects vary by not only pronunciation, but also, to a lesser extent, vocabulary and grammar. Modern written Chinese, which replaced Classical Chinese as the written standard as an indirect result of the May Fourth Movement of 1919, is not technically bound to any single variety; however, it most nearly represents the vocabulary and syntax of Mandarin, by far the most widespread Chinese dialectal family in terms of both geographical area and number of speakers. This version of written Chinese is called Vernacular Chinese, or 白話/白话 báihuà (literally, ``plain speech''). Despite its ties to the dominant Mandarin language, Vernacular Chinese also permits some communication between people of different dialects, limited by the fact that Vernacular Chinese expressions are often ungrammatical or unidiomatic in non-Mandarin dialects. This role may not differ substantially from the role of other linguae francae, such as Latin: For those trained in written Chinese, it serves as a common medium; for those untrained in it, the graphic nature of the characters is in general no aid to common understanding (characters such as ``one'' notwithstanding). In this regard, Chinese characters may be considered a large and inefficient phonetic script. However, Ghil'ad Zuckermann's exploration of phono-semantic matching in Standard Chinese concludes that the Chinese writing system is multifunctional, conveying both semantic and phonetic content.