Most linguists classify all varieties of modern spoken Chinese as part of the Sino-Tibetan language family and believe that there was an original language, termed Proto-Sino-Tibetan, from which the Sinitic and Tibeto-Burman languages descended. The relation between Chinese and other Sino-Tibetan languages is an area of active research, as is the attempt to reconstruct Proto-Sino-Tibetan. The main difficulty in this effort is that, while there is enough documentation to allow one to reconstruct the ancient Chinese sounds, there is no written documentation that records the division between Proto-Sino-Tibetan and ancient Chinese. In addition, many of the older languages that would allow us to reconstruct Proto-Sino-Tibetan are very poorly understood and many of the techniques developed for analysis of the descent of the (fusional) Indo-European languages from PIE do not apply to Chinese, an isolating language because of "morphological paucity" especially after Old Chinese.

Categorization of the development of Chinese is a subject of scholarly debate. One of the first systems was devised by the Swedish linguist Bernhard Karlgren in the early 1900s; most present systems rely heavily on Karlgren's insights and methods.

Old Chinese, sometimes known as "Archaic Chinese", was the language common during the early and middle Zhou Dynasty (1122 BCE–256 BCE), texts of which include inscriptions on bronze artifacts, the poetry of the Shījīng, the history of the Shūjīng, and portions of the Yìjīng (I Ching). The phonetic elements found in the majority of Chinese characters provide hints to their Old Chinese pronunciations. The pronunciation of the borrowed Chinese characters in Japanese, Vietnamese and Korean also provide valuable insights. Old Chinese was not wholly uninflected. It possessed a rich sound system in which aspiration or rough breathing differentiated the consonants, but probably was still without tones. Work on reconstructing Old Chinese started with Qīng dynasty philologists. Some early Indo-European loan-words in Chinese have been proposed, notably 蜜 mì "honey", 獅 shī "lion," and perhaps also 馬 mǎ "horse", 犬 quǎn "dog", and 鵝 é "goose". The source says the reconstructions of old Chinese are tentative, and not definitive so no conclusions should be drawn. The reconstruction of Old Chinese can not be perfect so this hypothesis may be called into question. The source also notes that southern dialects of Chinese have more monosyllabic words than the Mandarin Chinese dialects.

Middle Chinese was the language used during Southern and Northern Dynasties and the Suí, Táng, and Sòng dynasties (6th through 10th centuries CE). It can be divided into an early period, reflected by the "Qiēyùn" rime book (601 CE), and a late period in the 10th century, reflected by the "Guǎngyùn" rime book. Linguists are more confident of having reconstructed how Middle Chinese sounded. The evidence for the pronunciation of Middle Chinese comes from several sources: modern dialect variations, rhyming dictionaries, foreign transliterations, "rhyming tables" constructed by ancient Chinese philologists to summarize the phonetic system, and Chinese phonetic translations of foreign words. However, all reconstructions are tentative; some scholars have argued that trying to reconstruct, say, modern Cantonese from modern Cantopop rhymes would give a fairly inaccurate picture of the present-day spoken language.

The development of the spoken Chinese languages from early historical times to the present has been complex. Most Chinese people, in Sìchuān and in a broad arc from the north-east (Manchuria) to the south-west (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 middle and southern China promoted linguistic diversity.

Until the mid-20th century, most southern Chinese only spoke their native local variety of Chinese. As Nanjing was the capital during the early Ming Dynasty, Nanjing Mandarin became dominant at least until the later years of the Qing Dynasty. Since the 17th century, the Qing Dynasty had set up orthoepy academies (正音书院／正音書院; Zhèngyīn Shūyuàn) to make pronunciation conform to the standard of the capital Beijing. For the general population, however, this had limited effect. The non-Mandarin speakers in southern China also continued to use their various languages for every aspect of life. The Beijing Mandarin court standard was used solely by officials and civil servants and was thus fairly limited.

This situation did not change until the mid-20th century with the creation (in both the PRC and the ROC, but not in Hong Kong) of a compulsory educational system committed to teaching Mandarin. As a result, Mandarin is now spoken by virtually all young and middle-aged citizens of mainland China and on Taiwan. Cantonese, not Mandarin, was used in Hong Kong during the time of its British colonial period (owing to its large Cantonese native and migrant populace) and remains today its official language of education, formal speech, and daily life, but Mandarin is becoming increasingly influential after the 1997 handover.

Classical Chinese was once the lingua franca in neighbouring East Asian countries such as Japan, Korea and Vietnam for centuries, before the rise of European influences in the 19th century.[7] In Korea and Vietnam official documents were written in Chinese until the colonial period.