Chóngniǔ (simplified Chinese: 重纽; traditional Chinese: 重紐; literally: 'repeated button') or rime doublets are certain pairs of Middle Chinese syllables that are consistently distinguished in rime dictionaries and rime tables, but without a clear indication of the phonological basis of the distinction.
Rime dictionaries such as the Qieyun and Guangyun divided words by tone and then into rhyme groups. Each rhyme group was subdivided into homophone groups preceded by a small circle called a 紐 niǔ ("button"). The pronunciation of each homophone group was indicated by a fǎnqiè formula, a pair of characters having respectively the same initial and final sound as the word being described. By systematically analysing the fanqie, it is possible to identify equivalent initial and final spellers, and thus enumerate the initials and finals, but not their phonetic values. Rime tables such as the Yunjing further analysed the syllables distinguished by the rime dictionaries into initial consonant, "open" (kāi 開) or "closed" (hé 合), divisions (I–IV), broad rhyme class and tone. The closed distinction is generally considered to represent lip rounding.
The interpretation of the divisions has long been the most obscure part of traditional phonology. The finals implied by the fanqie may be divided into four broad classes based on the initials with which they co-occur. Because these classes correlate with rows in the rime tables, they are conventionally named divisions I–IV. Finals of divisions I, II and IV occur only in the corresponding rows of the rime tables, but division-III finals are spread across the second, third and fourth rows.
In most cases the different homophone groups within a Qieyun rhyme group are clearly distinguished by having a different initial or through the open/closed distinction in the rime tables. Pairs of syllables that are not so distinguished are known as chongniu, and occur only with certain division-III finals and with labial, velar or laryngeal initials. The distinction is reflected in the rime tables, where these pairs are divided between rows 3 and 4, and their finals are therefore known as division-III and division-IV chongniu finals respectively. The pairs are usually distinguished in fanqie spellings:
- The finals of division-III chongniu words are usually rendered with other division-III chongniu words, but sometimes with words with retroflex initials.
- The finals of division-IV chongniu words are rendered with other division-IV chongniu words or with words with acute initials.
Some Chinese authors refer to division-III and division-IV chongniu finals as types B and A respectively. The Middle Chinese notations of Li Fang-Kuei and William Baxter distinguish the division IV parts using spellings containing both "j" and "i", without any commitment to pronunciation:
|Rhyme group||Li's notation||Baxter's notation|
This distinction is generally not reflected in modern varieties of Chinese, with sporadic exceptions such as Beijing jì for chongniu-IV 悸 in contrast with guì for chongniu-III 匱 or bí for chongniu-IV 鼻 and bèi for chongniu-III 備. It is reflected most clearly in some Sino-Vietnamese and Sino-Korean readings:
Where division-IV chongniu finals follow velar or laryngeal initials, Sino-Korean shows a palatal glide. In Sino-Vietnamese, labial initials have become dentals before division-IV chongniu finals, possibly reflecting an earlier palatal element. Even so, some chongniu-IV words' labial initials remained labials in Sino-Vietnamese instead of becoming dentals.
According to the now prominent theory of Sergei Yakhontov, the chongniu-III syllables (together with all syllables in division II) had a medial *-r- in Old Chinese. William Baxter, following earlier ideas of Edwin Pulleyblank, suggested that chongniu-III syllables had medials *-rj- in Old Chinese, while their chongniu-IV counterparts had a medial *-j- before a front vowel. The later revision by Baxter and Laurent Sagart elides the *-j- medial, treating such "Type B" syllables as unmarked, in contrast to "Type A" syllables, which they reconstructed with pharyngealized initials. In this system, chongniu syllables were Type B syllables distinguished by the presence or absence of a medial *-r- in Old Chinese.
- Baxter (1992), pp. 33–35, 822.
- Norman (1988), p. 27.
- Baxter (1992), p. 33.
- Norman (1988), pp. 27–28.
- Pulleyblank (1984), pp. 142–143.
- Norman (1988), p. 32.
- Branner (2006), p. 15.
- Branner (2006), pp. 32–34.
- Baxter (1992), pp. 63–81.
- Baxter (1992), p. 75.
- Baxter (1977), pp. 60–61.
- Branner (2006), p. 25.
- Schuessler (2009), pp. 8-9.
- Pan & Zhang (2015), pp. 86-87.
- Baxter (1977), pp. 85–86.
- Baxter (1992), pp. 75–79.
- Baxter (1992), pp. 282–283.
- Meier & Payrot (2017), pp. 12-14.
- Baxter (1992), pp. 282–286.
- Baxter (1992), pp. 280–281.
- Baxter & Sagart (2014), pp. 215–217.
- Baxter, William H. (1977), Old Chinese Origins of the Middle Chinese Chóngniǔ Doublets: A Study Using Multiple Character Readings (Ph.D. thesis), Cornell University.
- ——— (1992), A Handbook of Old Chinese Phonology, Berlin: Mouton de Gruyter, ISBN 978-3-11-012324-1.
- Baxter, William H.; Sagart, Laurent (2014), Old Chinese: A New Reconstruction, Oxford University Press, ISBN 978-0-19-994537-5.
- Branner, David Prager (2006), "What are rime tables and what do they mean?", in Branner, David Prager (ed.), The Chinese Rime Tables: Linguistic Philosophy and Historical-Comparative Phonology, Studies in the Theory and History of Linguistic Science, Series IV: Current Issues in Linguistic Theory, 271, Amsterdam: John Benjamins, pp. 1–34, ISBN 978-90-272-4785-8.
- Meier, Kristin; Peyrot, Michaël (2017), "The Word for 'Honey' in Chinese, Tocharian and Sino-Vietnamese", Zeitschrift der Deutschen Morgenländischen Gesellschaft, 167 (1): 7–22, doi:10.13173/zeitdeutmorggese.167.1.0007.
- Norman, Jerry (1988), Chinese, Cambridge: Cambridge University Press, ISBN 978-0-521-29653-3.
- Pan, Wuyun; Zhang, Hongming (2015), "Middle Chinese Phonology and Qieyun", in Wang, William S-Y.; Sun, Chaofen (eds.), The Oxford Handbook of Chinese Linguistics, Oxford University Press, ISBN 978-0-1998-5633-6.
- Pulleyblank, Edwin G. (1984), Middle Chinese: a study in historical phonology, Vancouver: University of British Columbia Press, ISBN 978-0-7748-0192-8.
- Schuessler, Axel (2009), Minimal Old Chinese and Later Han Chinese: A Companion to Grammata Serica Recensa, Oxford University Press, ISBN 978-0-8248-3264-3.