Reconstructions of Old Chinese

Several authors have produced reconstructions of Old Chinese phonology, beginning with the Swedish sinologist Bernard Karlgren in the 1940s and continuing to the present day. The method employed is unique, comparing the categories of medieval rhyme dictionaries with categories implied by ancient rhyming practice and the structure of Chinese characters, though more recent approaches have also incorporated other kinds of evidence.

Although the various notations appear to be very different, they correspond with each other on most points. By the 1970s, it was generally agreed that Old Chinese had fewer points of articulation than Middle Chinese, a set of voiceless sonorants, and labiovelar and labio-laryngeal initials. Since the 1990s, most authors have agreed on a six-vowel system and a re-organized system of liquids. Earlier systems proposed voiced final stops to account for contacts between stop-final syllables and other tones, but many investigators now believe that Old Chinese lacked tonal distinctions, with Middle Chinese tones derived from consonant clusters at the end of the syllable.

The major sources for the sounds of Old Chinese, covering most of the lexicon, are the sound system of Middle Chinese (7th century AD), the structure of Chinese characters, and the rhyming patterns of the Classic of Poetry (Shijing), dating from the early part of the 1st millennium BC. Several other kinds of evidence are less comprehensive, but provide valuable clues. These include Min dialects, early Chinese transcriptions of foreign names, early loans between Chinese and neighbouring languages, and families of Chinese words that appear to be related.

Middle Chinese, or more precisely Early Middle Chinese, is the phonological system of the Qieyun, a rhyme dictionary published in 601, with many revisions and expansions over the following centuries. These dictionaries indicated pronunciation by dividing a syllable into an initial consonant and the rest, called the final. In his Qièyùn kǎo (1842), the Cantonese scholar Chen Li performed a systematic analysis of a later redaction of the Qieyun, identifying its initial and final categories, though not the sounds they represented. Scholars have attempted to determine the phonetic content of the various distinctions by comparing them with rhyme tables from the Song dynasty, pronunciations in modern varieties and loans in Korean, Japanese and Vietnamese (the Sinoxenic materials), but many details regarding the finals are still disputed. According to its preface, the Qieyun did not reflect a single contemporary dialect, but incorporated distinctions made in different parts of China at the time (a diasystem).

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