Old Chinese phonology

Scholars have attempted to reconstruct the phonology of Old Chinese from documentary evidence. Although the writing system does not describe sounds directly, shared phonetic components of the most ancient Chinese characters are believed to link words that were pronounced similarly at that time. The oldest surviving Chinese verse, in the Classic of Poetry (Shijing), shows which words rhymed in that period. Scholars have compared these bodies of contemporary evidence with the much later Middle Chinese reading pronunciations listed in the Qieyun rhyme dictionary published in 601 AD, though this falls short of a phonemic analysis. Supplementary evidence has been drawn from cognates in other Sino-Tibetan languages and in Min Chinese, which split off before the Middle Chinese period, Chinese transcriptions of foreign names, and early borrowings from and by neighbouring languages such as Hmong–Mien, Tai and Tocharian languages.

Although many details are disputed, most recent reconstructions agree on the basic structure. It is generally agreed that Old Chinese differed from Middle Chinese in lacking retroflex and palatal obstruents but having initial consonant clusters of some sort, and in having voiceless sonorants. Most recent reconstructions also posit consonant clusters at the end of the syllable, developing into tone distinctions in Middle Chinese.

The reconstruction of Old Chinese typically starts from "Early Middle Chinese", the phonological system of the Qieyun, a rhyme dictionary published in 601, with many revisions and expansions over the following centuries. According to its preface, the Qieyun did not record a single contemporary dialect, but set out to codify the pronunciations of characters to be used when reading the classics, incorporating distinctions made in different parts of China at the time (a diasystem).^[1]

The Qieyun and its successors grouped characters by tone class, rhyme group and homophone group. The pronunciation of each group of homophonous characters was indicated using the fanqie method, using a pair of other words with the same initial consonant and final (the rest of the syllable) respectively.^[2] Analysis of the fanqie spellings allows one to enumerate the initials and finals of the system, but not to determine their phonetic values.^[3] The rhyme tables from the Song dynasty contain a sophisticated feature analysis of the Qieyun initials and finals, though they were influenced by the different pronunciations of that later period.^[4][5] Scholars have attempted to determine the phonetic content of the initials and finals by comparing them with the rhyme tables and by examining pronunciations in modern varieties and loans in Japanese, Korean and Vietnamese (the Sinoxenic materials), but many details regarding the finals are still uncertain.^[6][7]

In the rhyme table tradition, initials were classified by place and manner of articulation.^[8] The initials of the Qieyun are slightly different from the rhyme tables, but generally agreed and each traditionally named with an exemplary word as follows:^[9][10]

Initials of Early Middle Chinese with traditional names and Baxter's notation^[a]

		Labial[b]	Dental[c]	Retroflex stop	Dental sibilant	Retroflex sibilant	Palatal[d]	Velar	Laryngeal[e]
Stop or affricate	voiceless	幫 p-	端 t-	知 tr-	精 ts-	莊 tsr-	章 tsy-	見 k-	影 ʔ-
	aspirate	滂 ph-	透 th-	徹 trh-	清 tsh-	初 tsrh-	昌 tsyh-	溪 kh-
	voiced	並 b-	定 d-	澄 dr-	從 dz-	崇 dzr-	禪 dzy-[f]	群 g-
Nasal		明 m-	泥 n-	娘 nr-			日 ny-	疑 ng-
Fricative	voiceless				心 s-	生 sr-	書 sy-		曉 x-
	voiced				邪 z-	俟 zr-[g]	船 zy-[f]		匣/云 h-[h]
Approximant			來 l-				以 y-[h]

Many potential combinations of initial and final did not occur. To save space, the designers of the rhyme tables separated finals with different patterns of co-occurrence, effectively identifying cases of complementary distribution.^[19] Thus finals are split between divisions (等 děng) I, II, III and IV based on the rows of the rhyme tables in which they were placed.^[20] Most scholars believe that division III finals were characterized by a palatal medial -j- in Middle Chinese.^[21]

Division III finals occur in more than half of the syllables of the Qieyun. Some authors call them type B finals, with type A encompassing all the other divisions.^[22] Comparing placement in the rhyme tables with distribution in the Qieyun, Li Rong subdivided division III finals into four distributional classes, which others have called pure (or independent), mixed and two kinds called chongniu.^[23][24][25] Some of the distinctions between the resulting seven classes are found only in the rhyme tables. When considering the Qieyun only, they reduce to four distinct patterns of co-occurrence with initials at various places of articulation:^[26]

Co-occurrence of classes of Qieyun initials and finals

Qieyun final type		Qieyun initial type
		Labial	Dental	Retroflex stop	Dental sibilant	Retroflex sibilant	Palatal	Velar	Laryngeal
Type A	Divisions I and IV	yes	yes		yes			yes	yes
	Division II	yes		yes		yes		yes	yes
Type B (div. III)	Pure and chongniu-4	yes						yes	yes
	Mixed and chongniu-3	yes		yes	yes	yes	yes	yes	yes

The rhyme tables classified Qieyun finals as either 'open' (開 kāi) or 'closed' (合 hé), with the latter believed to indicate a medial -w- or lip rounding.^[20]

Each character of the script represented a single Old Chinese morpheme, originally identical to a word.^[27] The system does not use symbols for individual sounds as is done in an alphabetic system.^[28] However, while a minority of words are represented pictorially, most are written by borrowing characters for similar-sounding words, often adding a disambiguating element. As a result, the vast majority of characters are phono-semantic compounds, in which a word is written by combining a character for a similarly sounding word with a semantic indicator.^[29] Often the characters sharing a phonetic element (forming a phonetic series) are still pronounced alike, as in the character 中 (zhōng, 'middle'), which was adapted to write the words chōng ('pour', 沖) and zhōng ('loyal', 忠).^[30] In other cases the words in a phonetic series have very different sounds in any known variety of Chinese, but are assumed to have been similar in sound at the time the characters were chosen.^[31]

The first systematic study of the structure of Chinese characters was Xu Shen's Shuowen Jiezi (100 AD).^[32] The Shuowen was mostly based on the small seal script standardized in the Qin dynasty.^[33] Earlier characters from oracle bones and Zhou bronze inscriptions often reveal relationships that were obscured in later forms.^[34] Since the late 20th century, several caches of Bamboo and wooden slips from the Warring States period have been recovered, featuring a wider variety of pre-Qin characters than the formulaic bone and bronze inscriptions.^[35]

The other large body of contemporaneous evidence is rhyme in ancient texts. Most work has focussed on the Shijing, a collection of songs and poetry from the 11th to 7th centuries BC.^[36] Again some of these songs still rhyme in modern varieties of Chinese, but many do not. This was attributed to lax rhyming practice until the late-Ming dynasty scholar Chen Di argued that a former consistency had been obscured by sound change.^[37][38] The systematic study of Old Chinese rhymes began in the 17th century, when Gu Yanwu divided the rhyming words of the Shijing into ten rhyme groups (yùnbù 韻部).^[39] These groups were subsequently refined by other scholars, culminating in a standard set of 31 in the 1930s. One of these scholars, Duan Yucai, stated the important principle that characters in the same phonetic series would be in the same rhyme group,^[i] making it possible to assign almost all words to rhyme groups.^[41][31]

Modern Min dialects, particularly those of northwest Fujian, show reflexes of distinctions not reflected in Middle Chinese. For example, the following dental initials have been identified in reconstructed proto-Min:^[42][43]

	Voiceless stops			Voiced stops			Nasals		Laterals
Example word	單	轉	炭	直	長	頭	南	年	來	老
Proto-Min initial	*t	*-t	*th	*d	*-d	*dh	*n	*nh	*l	*lh
Middle Chinese initial	t		th	d			n		l

Other points of articulation show similar distinctions within stops and nasals. Proto-Min voicing is inferred from the development of Min tones, but the phonetic values of the initials are otherwise uncertain. The sounds indicated as *-t, *-d, etc. are known as "softened stops" due to their reflexes in Jianyang and nearby Min varieties in northwestern Fujian, where they appear as fricatives or approximants (e.g. [v l h] < *-p *-t *-k in Jianyang) or are missing entirely, while the non-softened variants appear as stops. Evidence from early loans into Yao languages suggests that the softened stops were prenasalized.^[44] The distinction among resonants is also reflected in some Hakka varieties.^[45]

The Waxiang dialects of western Hunan differ strongly from other Chinese varieties, preserving several distinctions and features not found in the Qieyun.^[46]

Most scholars believe that Old Chinese morphemes were overwhelmingly monosyllabic, though some have recently suggested that a minority of them had minor presyllables (but still written with a single character).^[27][47]

Although many details of the sound system are still disputed, recent formulations are in substantial agreement on the core issues.^[48] For example, the Old Chinese initial consonants recognized by Li Fang-Kuei and William Baxter are given below, with Baxter's (mostly tentative) additions given in parentheses:^{[49][50][51][j]}

		Labial	Dental		Palatal [k]	Velar		Laryngeal
			plain	sibilant		plain	labialized	plain	labialized
Stop or affricate	voiceless	*p	*t	*ts		*k	*kʷ	*ʔ	*ʔʷ
	aspirate	*pʰ	*tʰ	*tsʰ		*kʰ	*kʷʰ
	voiced	*b	*d	*dz		*ɡ	*ɡʷ
Nasal	voiceless	*m̥	*n̥			*ŋ̊	*ŋ̊ʷ
	voiced	*m	*n			*ŋ	*ŋʷ
Lateral	voiceless		*l̥
	voiced		*l
Fricative or approximant	voiceless		(*r̥)	*s	(*j̊)			*h	*hʷ
	voiced		*r	(*z)	(*j)			(*ɦ)	(*w)

Most scholars reconstruct clusters of *s- with other consonants, and possibly other clusters as well, but this area remains unsettled.^[54]

In recent reconstructions, such as the widely accepted system of Baxter (1992), the rest of the Old Chinese syllable consists of

• an optional medial *-r-,
• an optional medial *-j- or (in some reconstructions) some other representation of a distinction between "type-A" and "type-B" syllables,
• one of six vowels:

*i	*ə	*u
*e	*a	*o

• an optional coda, which could be a glide *-j or *-w, a nasal *-m, *-n or *-ŋ, or a stop *-p, *-t, *-k or *-kʷ,
• an optional post-coda *-ʔ or *-s.

In such systems, Old Chinese has no tones; the rising and departing tones of Middle Chinese are treated as reflexes of the Old Chinese post-codas.^[55]

The primary sources of evidence for the reconstruction of the Old Chinese initials are medieval rhyme dictionaries and phonetic clues in the Chinese script.

Early in the 20th century, Huang Kan proposed that the division I and IV finals, and the initials with which they occurred, namely labials, dentals, dental sibilants, velars and laryngeals, were primitive.^[56][10] Most scholars believe that finals of divisions I and IV contained back and front vowels respectively. Division II is believed to represent retroflexion, and is traced back to the Old Chinese *-r- medial discussed above, while division III is usually taken as indicating a -j- medial.^[57][58] Since Karlgren, many scholars have projected this medial (but not -w-) back onto Old Chinese.

It is possible to account for the combinations of initials and finals of the Qieyun by combining these initials with Old Chinese medials *-r- and *-j-. The following table shows Baxter's account of the Old Chinese initials and medials leading to the combinations of initial and final types found in Early Middle Chinese.^[59][60]

Reconstructed Old Chinese initials and medials

Qieyun final type		Qieyun initial type
		Labial	Dental	Retroflex stop	Dental sibilant	Retroflex sibilant	Palatal	Velar	Laryngeal
Type A	Divisions I and IV	*P-	*T-		*TS-			*K-	*Q-
	Division II	*Pr-		*Tr-		*TSr-		*Kr-	*Qr-
Type B (div. III)	Pure and chongniu-4	*Pj-						*Kj-	*Qj-
	Mixed and chongniu-3	*Prj-		*Trj-	*TSj-	*TSrj-	*Tj-, *Kj-	*Krj-	*Qrj-

Here *P, *T, *TS, *K and *Q stand for consonant classes in Old Chinese. The Qing philologist Qian Daxin had already discovered, by studying sound glosses given by Eastern Han authors, that the Middle Chinese dental and retroflex stop series were not distinguished at that time.^[61][62]

The Middle Chinese -w- medial was unevenly distributed, being distinctive only after velar and laryngeal initials or before -aj, -an or -at. This is taken (following André-Georges Haudricourt and Sergei Yakhontov) to indicate that Old Chinese had labiovelar and labiolaryngeal initials but no labiovelar medial.^[63] The remaining occurrences of Middle Chinese -w- are believed to result from breaking of a back vowel before these codas (see § Vowels).^[64][65]

A key principle, first proposed by the Swedish sinologist Bernhard Karlgren, holds that the initials of words written with the same phonetic component had a common point of articulation in Old Chinese. For example, since Middle Chinese dentals and retroflex stops occur together in phonetic series, they are traced to a single Old Chinese dental series, with the retroflex stops conditioned by an Old Chinese medial *-r-. The Middle Chinese dental sibilants and retroflex sibilants also occur interchangeably in phonetic series, and are similarly traced to a single Old Chinese sibilant series, with the retroflex sibilants conditioned by the Old Chinese medial *-r-.^[66][67][l]

However, there are several cases where quite different Middle Chinese initials appear together in a phonetic series. Karlgren and subsequent workers have proposed either additional Old Chinese consonants or initial consonant clusters in such cases. For example, the Middle Chinese palatal sibilants appear in two distinct kinds of series, with dentals and with velars:^[m]

• 周 tsyuw (< *tj-) 'cycle; Zhou dynasty', 彫 tew (< *t-) 'carve' and 調 dew (< *d-) 'adjust'^[70][71]
• 制 tsyejH (< *kj-) 'cut out' and 猘 kjejH (< *krj-) 'mad dog'^[72][73]

It is believed that Old Chinese dentals followed by an Old Chinese medial *-j- were palatalized, unless the medial *-r- was also present. Some Old Chinese velars were also palatalized, but the conditioning factors are only partly understood.^[74] Li proposed *Krj- as the source of palatal initials occurring in phonetic series with velars or laryngeals, found no evidence for *Prj-, and attributed the chóngniǔ distinction to the vowel. Following proposals by Pulleyblank, Baxter explained chóngniǔ using *-rj- and postulated that plain velars and laryngeals were palatalized when followed by both *-j- (but not *-rj-) and a front vowel. However a significant number of palatalizations are not explained by this rule.^[59][75][76]

Similarly, it is proposed that the *-r- medial could occur after labials and velars, complementing the instances proposed as sources of Middle Chinese retroflex dentals and sibilants, to account for such connections as:^[77][78][n]

• 筆 pit (< *pr-) 'writing pencil' and 律 lwit (< *br-) 'law; rule'^[80][81]
• 監 kaem (< *kr-) 'look at' and 藍 lam (< *ɡr-) 'indigo'^[82][83]

Thus the Middle Chinese lateral l- is believed to reflect Old Chinese *-r-. Old Chinese voiced and voiceless laterals *l- and *l̥- are proposed to account for a different group of series such as

• 脫 dwat (< *l-) and thwat (< *l̥-) 'peel off', 悅 ywet (< *lj-) 'pleased' and 說 sywet (< OC *l̥j-) 'speak'^[84][85][o]

This treatment of the Old Chinese liquids is further supported by Tibeto-Burman cognates and by transcription evidence. For example, the name of a city (Alexandria Ariana or Alexandria Arachosia) was transcribed in the Book of Han chapter 96 as ⟨烏弋山離⟩, which is reconstructed as *ʔa-ljək-srjan-rjaj.^[86][87] Traces of the earlier liquids are also found in the divergent Waxiang dialect of western Hunan.^[88]

Voiceless nasal initials *m̥-, *n̥- and *ŋ̊- are proposed (following Dong Tonghe and Edwin Pulleyblank) in series such as:^[89]

• 墨 mok 'ink' and 黑 xok (< *m̥-) 'black'^[90][91]
• 難 nan 'difficult' and 灘 than (< *n̥-) 'foreshore'^[92][93]
• 虐 ngjak 'cruel' and 謔 xjak (< *ŋ̊-) 'to ridicule'^[94][95]

Clusters *sn- and so on are proposed (following Karlgren) for alternations of Middle Chinese nasals and s- such as

• 如 nyo (< *nj-) 'resemble' and 絮 sjoH (< *snj-) 'raw silk'^[96][97]

Other cluster initials, including *s with stops or stops with *l, have been suggested but their existence and nature remains an open question.^[98][99]

Proto-Min *nh and *lh are distinct from the Old Chinese initials *n̥ and *l̥, which both yield Middle Chinese th (or sy in palatal environments).^[100][101] The distinctions found in Proto-Min initials are assumed by most workers to date from the Old Chinese period, but they are not reflected in the widely accepted inventory of Old Chinese initials given above. The Old Chinese antecedents of these distinctions are not yet agreed, with researchers proposing a variety of consonant clusters.^[102][p]

As Middle Chinese g- occurs only in palatal environments, Li attempted to derive both g- and h- from Old Chinese *ɡ-, but had to assume irregular developments in some cases. Li Rong showed that several words with Middle Chinese initial h- were distinguished in modern Min dialects. For example, 厚 'thick' and 後 'after' were both huwX in Middle Chinese, but have velar and zero initials respectively in several Min dialects. Most authors now assume both *ɡ- and *ɦ-, with subsequent lenition of *ɡ- in non-palatal environments. Similarly *w- is assumed as the labialized counterpart of *ɦ-.^{[104][105][106]}

Pan Wuyun has proposed a revision of the above scheme to account for the fact that Middle Chinese glottal stop and laryngeal fricatives occurred together in phonetic series, unlike dental stops and fricatives, which were usually separated. Instead of the glottal stop initial *ʔ- and fricatives *h- and *ɦ-, he proposed uvular stops *q-, *qʰ- and *ɢ-, and similarly labio-uvular stops *qʷ-, *qʷʰ- and *ɢʷ- in place of *ʔʷ-, *hʷ- and *w-.^[107][108]

Although many authors have projected the Middle Chinese palatal medial -j- back to a medial *-j- in Old Chinese, others have suggested that the Middle Chinese medial was a secondary development not present in Old Chinese. Evidence includes the use of type B syllables to transcribe foreign words lacking any such medial, the lack of the medial in Tibeto-Burman cognates and modern Min reflexes, and the fact that it is ignored in phonetic series.^[109][110] Nonetheless, scholars agree that the difference reflects a real phonological distinction of some sort, often described noncommittally as a distinction between type A and B syllables using a variety of notations.^{[111][112][113]} The distinction has been variously ascribed to:

• the presence or absence of a prefix. Jakhontov held that type B reflected a prefix *d-,^[112][22] while Ferlus suggested that type A arose from an unstressed prefix *Cə- (a minor syllable), which conditioned syllabic tenseness contrasting with laxness in type B syllables.^[114]
• a length distinction of the main vowel. Pulleyblank initially proposed that type B syllables had longer vowels.^[115] Later, citing cognates in other Sino-Tibetan languages, Starostin and Zhengzhang independently proposed long vowels for type A and short vowels for type B.^{[116][117][118]} The latter proposal might explain the description in some Eastern Han commentaries of type A and B syllables as huǎnqì 緩氣 'slow breath' and jíqì 急氣 'fast breath' respectively.^[119]
• a prosodic stress-based distinction, as later proposed by Pulleyblank,^[115] in which type B syllables were stressed in the first mora, while type A syllables were stressed on the second^[120]
• pharyngealization of the initial consonant. Norman suggested that type B syllables (his class C), which comprised over half of the syllables of the Qieyun, were in fact unmarked in Old Chinese. Instead, he proposed that the remaining syllables were marked by retroflexion (the *-r- medial) or pharyngealization, either of which prevented palatalization in Middle Chinese.^[121] Baxter and Sagart have adopted a variant of this proposal, reconstructing pharyngealized initials in all type A syllables.^[122]

Assuming that rhyming syllables had the same main vowel, Li Fang-Kuei proposed a system of four vowels *i, *u, *ə and *a. He also included three diphthongs *iə, *ia and *ua to account for syllables that were placed in rhyme groups reconstructed with *ə or *a but were distinguished in Middle Chinese.^[123] In the late 1980s, Zhengzhang Shangfang, Sergei Starostin and William Baxter (following Nicholas Bodman) independently argued that these rhyme groups should be split, refining the 31 traditional rhyme groups into more than 50 groups corresponding to a six-vowel system.^{[124][125][126][127][128]} Baxter supported this thesis with a statistical analysis of the rhymes of the Shijing, though there were too few rhymes with codas *-p, *-m and *-kʷ to produce statistically significant results.^[129]

The following table illustrates these analyses, listing the names of the 31 traditional rhyme groups with their Middle Chinese reflexes and their postulated Old Chinese vowels in the systems of Li and Baxter. Following the traditional analysis, the rhyme groups are organized into three parallel sets, depending on the corresponding type of coda in Middle Chinese. For simplicity, only Middle Chinese finals of divisions I and IV are listed, as the complex vocalism of divisions II and III is believed to reflect the influence of Old Chinese medials *-r- and *-j- (see previous section).^[130][q]

Shijing rhyme groups and Middle Chinese reflexes in divisions I and IV								OC vowels
MC vocalic coda 陰聲 yīnshēng				MC stop coda 入聲 rùshēng		MC nasal coda 陽聲 yángshēng		Li	Baxter
				緝 qì	-ep	侵 qīn	-em	*-iə-	*-i-
					-op		-om	*-ə-	*-ə-, *-u-
				葉 yè / 盍 hé	-ep	談 tán	-em	*-ia-	*-e-
					-ap		-am	*-a-	*-a-, *-o-
脂 zhī	-ej			質 zhì	-et	真 zhēn	-en	*-i-	*-i-
微 wēi	-ej			物 wù / 術 shù	-et	文 wén / 諄 zhūn	-en	*-iə-	*-ə-
	-oj				-ot		-on	*-ə-	*-u-
		祭 jì[r]	-ej	月 yuè	-et	元 yuán / 寒 hán	-en	*-ia-	*-e-
歌 gē	-a		-aj		-at		-an	*-a-	*-a-
	-wa		-waj		-wat		-wan	*-ua-	*-o-
支 zhī / 佳 jiā	-ej			錫 xī	-ek	耕 gēng	-eng	*-i-	*-e-
之 zhī	-oj			職 zhí	-ok	蒸 zhēng	-ong	*-ə-	*-ə-
魚 yú	-u			鐸 duó	-ak	陽 yáng	-ang	*-a-	*-a-
侯 hóu	-uw			屋 wū	-uwk	東 dōng	-uwng	*-u-	*-o-
幽 yōu	-aw			覺 jué / 沃 wò	-owk	冬 dōng / 中 zhōng	-owng	*-ə-ʷ	*-u-
	-ew				-ek			*-iə-ʷ	*-i-ʷ
宵 xiāo	-aw			藥 yào	-ak, -owk, -uwk			*-a-ʷ	*-a-ʷ
	-ew				-ek			*-ia-ʷ	*-e-ʷ
-ʷ: Old Chinese finals reconstructed with labiovelar codas

There has been much controversy over the relationship between final consonants and tones, and indeed whether Old Chinese lacked the tones characteristic of later periods, as first suggested by the Ming dynasty scholar Chen Di.^[s]

The four tones of Middle Chinese were first described by Shen Yue around AD 500. They were the 'level' (平 píng), 'rising' (上 shǎng), 'departing' (去 qù), and 'entering' (入 rù) tones, with the last category consisting of the syllables ending in stops (-p, -t or -k).^[133] Although rhymes in the Shijing usually respect these tone categories, there are many cases of characters that are now pronounced with different tones rhyming together in the songs, mostly between the departing and entering tones. This led Duan Yucai to suggest that Old Chinese lacked the departing tone. Wang Niansun (1744–1832) and Jiang Yougao (d.1851) decided that the language had the same tones as Middle Chinese, but some words had later shifted between tones, a view that is still widely held among linguists in China.^[134][135]

Karlgren also noted many cases where words in the departing and entering tones shared a phonetic element within their respective characters, e.g.

• 賴 lajH 'depend on' and 剌 lat 'wicked'^[136]
• 欬 khojH 'cough' and 刻 khok 'cut; engrave'^[137]

He suggested that the departing tone words in such pairs had ended with a final voiced stop (*-d or *-ɡ) in Old Chinese.^[138] Being unwilling to split rhyme groups, Dong Tonghe and Li Fang-Kuei extended these final voiced stops to whole rhyme groups. The only exceptions were the 歌 and 祭 groups (Li's *-ar and *-ad), in which the traditional analysis already distinguished the syllables with entering tone contacts. The resulting scarcity of open syllables has been criticized on typological grounds.^[139] Wang Li preferred to reallocate words with connections to the entering tone to the corresponding entering tone group, proposing that the final stop was lost after a long vowel.^[140]

Another perspective is provided by Haudricourt's demonstration that the tones of Vietnamese, which have a very similar structure to those of Middle Chinese, were derived from earlier final consonants. The Vietnamese counterparts of the rising and departing tones derived from a final glottal stop and *-s respectively, the latter developing to a glottal fricative *-h. These glottal post-codas respectively conditioned rising and falling pitch contours, which became distinctive when the post-codas were lost.^[141] Haudricourt also suggested that the Chinese departing tone reflected an Old Chinese derivational suffix *-s. The connection with stop finals would then be explained as syllables ending with *-ts or *-ks, with the stops later disappearing, allowing rhymes with open syllables.^[142] The absence of a corresponding labial final could be attributed to early assimilation of *-ps to *-ts. Pulleyblank supported the theory with several examples of syllables in the departing tone being used to transcribe foreign words ending in -s into Chinese.^{[143][144][145]}

Pulleyblank took Haudricourt's suggestion to its logical conclusion, proposing that the Chinese rising tone had also arisen from a final glottal stop.^[146] Mei Tsu-lin supported this theory with evidence from early transcriptions of Sanskrit words, and pointed out that rising tone words end in a glottal stop in some modern Chinese dialects, e.g. Wenzhounese and some Min dialects.^[147] In addition, most of the entering tone words that rhyme with rising tone words in the Shijing end in -k.^[148]

Together, these hypotheses lead to the following set of Old Chinese syllable codas:^[149]

MC vocalic coda				MC stop coda	MC nasal coda
平	上	去		入	平	上	去
				*-p	*-m	*-mʔ	*-ms
*-j	*-jʔ	*-js	*-ts	*-t	*-n	*-nʔ	*-ns
*-∅	*-ʔ	*-s	*-ks	*-k	*-ŋ	*-ŋʔ	*-ŋs
*-w	*-wʔ	*-ws	*-kʷs	*-kʷ

Baxter also speculated on the possibility of a glottal stop occurring after oral stop finals. The evidence is limited, and consists mainly of contacts between rising tone syllables and -k finals, which could alternatively be explained as phonetic similarity.^[150]

To account for phonetic series and rhymes in which MC -j alternates with -n, Sergei Starostin proposed that MC -n in such cases derived from Old Chinese *-r.^[151] Other scholars have suggested that such contacts are due to dialectal mixture, citing evidence that *-n had disappeared from eastern dialects by the Eastern Han period.^[152]

• Historical Chinese phonology

Tutorials

• "Introduction to Chinese Historical Phonology", Guillaume Jacques, European Association of Chinese Linguistics Spring School in Chinese Linguistics, International Institute for Asian Studies, Leiden, March 2006.
• "Summer School on Old Chinese Phonology" (videos), William Baxter and Laurent Sagart, École des Hautes Études en Sciences Sociales, Paris, July 2007.

Databases of reconstructions

• StarLing database, by Georgiy Starostin.
• The Baxter-Sagart reconstruction of Old Chinese.
• 上古音系- 韻典網
• 小學堂上古音 - 中央研究院
• 李方桂上古音韻表