but probably was still without tones. Work on reconstructing Old Chinese started with Qing dynasty philologists. Middle Chinese Middle Chinese was the language used during the Sui dynasty (隋朝), Tang dynasty(唐朝), and Song dynasty(宋朝), or the sixth to tenth centuries AD. It can be divided into an early period, which can be shown by the Qieyun rime dictionary (AD 601) and its later redaction the Guangyun, and a late period in the tenth century, reflected by rime tables such as the Yunjing. The evidence for the pronunciation of Middle Chinese comes from several sources: modern dialect variations, rime dictionaries, foreign transliterations, rime tables constructed by ancient Chinese philologists to summarize the phonetic system, and Chinese phonetic translations of foreign words. Spoken Chinese The development of the spoken Chinese from early historical times to the present has been complex. Most Chinese people, in Sichuan and in a broad arc from the northeast (Manchuria) to the southwest (Yunnan), use various Mandarin dialects as their home language. The prevalence of Mandarin throughout northern China is largely due to north China's plains. By contrast, the mountains and rivers of southern China favoured linguistic diversity. Until the mid-20th century, most southern Chinese only spoke their native local variety of Chinese. However, despite the mix of officials and commoners speaking various Chinese dialects, Nanjing Mandarin became dominant at least during the Qing dynasty. Since the 17th century, the Empire had already been setting up orthoepy academies () to make pronunciation conform to the Qing capital Beijing's standard, but had little success. During the Qing's last 50 years in the late 19th century, the Beijing Mandarin finally replaced Nanjing Mandarin in the imperial court. For the general population, although variations of Mandarin were already widely spoken in China then, a single standard of Mandarin did not exist. The non-Mandarin speakers in southern China also continued to use their local languages for each and every aspect of life. The new Beijing Mandarin court standard was thus fairly limited. This situation changed with the creation (in both the PRC and the ROC, but not in Hong Kong and Macau) of an elementary school education system committed to teaching Modern Standard Chinese (Mandarin). As a result, Mandarin is now spoken by virtually all people in mainland China and on Taiwan. At the time of the widespread introduction of Mandarin in mainland China and Taiwan, Hong Kong was a British colony