In the medieval rime dictionaries, characters were organized into rhyme groups ( ), with 193 groups in the
Qieyun, growing to 206 in the
Guangyun. The order of the rhyme groups within each tone implies a correspondence between rhyme groups across the
four tones. Thus for each rhyme group with an -m, -n or -ng coda in the level tone there are typically corresponding rhyme groups with the same coda in the rising and departing tones, and a corresponding rhyme group in the
entering tone with a -p, -t or -k coda respectively. In contrast, syllables with vocalic codas typically had corresponding rhyme groups only in the level, rising and departing tones. There were also four departing tone rhyme groups with -j codas that had no counterparts in the other tones. The rime tables were solely concerned with the pronunciation of syllables of these rime dictionaries, and do not contain dictionary-like material such as definitions. Similarly, where a group of characters are recorded as
homophones in the rime dictionaries, typically only one will occur in a rime table. A rime table book presents these distinct syllables in a number of tabular charts, each devoted to one or more sets of parallel rhyme groups across the tones. The preface to
Qieyun indicates that it represented a compromise between northern and southern reading pronunciations from the late
Northern and Southern dynasties period. Most linguists now believe that no single dialect contained all the distinctions it recorded, but that each distinction did occur somewhere. The rime tables were compiled centuries later in the time of a new standard, and many of the distinctions in the
Qieyun would have been meaningless to the compilers.
Edwin Pulleyblank has argued that the tables contain enough evidence to reconstruct the speech of that later period. He calls this language Late Middle Chinese (LMC) in contrast to the Early Middle Chinese of the
Qieyun, and argues that it was the standard speech of the imperial capital
Chang'an in the late
Tang dynasty. His reconstruction accounts for most of the distinctions in modern varieties of Chinese (except
Min), as well as layers of Chinese loanwords, such as the
Kan-on layer of
Sino-Japanese vocabulary.
Tables Each chart of the
Yunjing is labelled as either "open" ( ) or "closed" (). The corresponding terms in the
Qiyin lüe are "heavy" () and "light" (). The open/closed distinction is interpreted to indicate the absence or presence of lip rounding (often transcribed as -w- or -u-). Some
Guangyun rhyme groups include syllables of both kinds, and thus span two charts, while others are purely "open" or "closed", and thus fit within one chart. Charts are grouped together in broad rhyme classes (), each characterized as either "inner" () or "outer" (), thought to be related to vowel heights, contrasting
close vowels and
open vowels respectively. For example, the first of the 43 charts of the
Yùnjìng is shown below (the Arabic numerals are modern annotations): The five big characters on the right-hand side read (內轉第一開). In the
Yùnjìng, each chart is called (lit. 'turn'). The characters indicate that the chart is the first (第一) one in the book, and that the syllables of this chart are "inner" (內) and "open" (開). The columns of each table classify syllables according to their initial consonant ( 聲母 lit. 'sound mother'), with syllables beginning with a
vowel considered to have a "zero initial". Initials are classified according to •
place of articulation:
labials ( 脣 'lip'),
alveolars ( 舌 'tongue'),
velars ( 牙 'back tooth'),
affricates and
sibilants ( 齒 "front tooth"), and laryngeals ( 喉 'throat'). The values of the last category remain controversial. •
manner of articulation: voiceless ( 清 'clear'), voiceless aspirated ( 次清 'secondary clear'), voiced ( 濁 'muddy') or
nasal or
liquid ( 清濁 'clear muddy'). The order of the places and manners roughly match that of
Sanskrit, providing further evidence of inspiration from Indian phonology. Each table had 16 rows, with a group of four rows for each of the four tones of the
Qieyun. The above chart covers four parallel
Guangyun rhyme groups, the level-toned , the rising-toned , the departing-toned , and the entering-toned (which in Middle Chinese ended in -k, the entering tone counterpart of -ng). Within each tone group are four rows known as (等 'class', 'grade' or 'group'), which
Bernhard Karlgren translated as "divisions" while other linguists prefer "grades". They are usually denoted by Roman numerals I to IV. Their meaning remains the most controversial aspect of rime table phonology, but is believed to indicate
palatalization (transcribed as the presence or absence of -j- or -i-),
retroflex features,
phonation, vowel quality (high vs. low or front vs. back) or some combination of these. Other scholars view them not as phonetic categories but formal devices exploiting distributional patterns in the
Qieyun to achieve a compact presentation. The symbol ○ indicates that that particular syllable does not occur.
Bernard Karlgren noticed that classes of finals from the rime dictionaries were placed in different rows of the rime tables. As three classes of final occurred in the first, second and fourth rows respectively, he named them finals of divisions I, II and IV. The remaining finals he called "division-III finals" because they occurred in the third row of the tables. Some of these (the "pure" division-III finals) occurred only in that row, while others (the "mixed" finals) could also occur in the second or fourth rows with some initials. Later workers noted that in the so-called chongniu| rhyme groups, , , , , , , and , a consistent distinction within each rhyme group in the rime books is reflected in the rime tables by dividing the rhyme group between rows 2 and 4, often in adjacent tables.
Li Rong, in a systematic comparison of the rhyme tables with a recently discovered early edition of the , identified seven classes of finals. The table below lists the combinations of initial and final classes that occur in the , with the row of the rime tables in which each combination was placed: The mixed and finals, though designated as division-III finals, are spread across rows 2 and 4 as well as row 3 of the tables. To handle these cases, a distinction is made between the row that the homophone class is placed in and the "division" of its final. This article distinguishes rows by
Arabic numerals 1 2 3 4 and divisions by
Roman numerals I II III IV. In addition, division-II and division-IV finals occur only in "outer" . This distribution is the foundation of the compact tabular presentation of rime dictionary syllables. For example, the dental and retroflex stop initials are combined in a single group in a rime table, with the rows distinguishing the different initials, and the three groups of sibilant initials are similarly combined. In a similar fashion different finals may occupy different rows of the same chart. The rhyme groups (here illustrated in the level tone, except where a group occurs only in the departing tone) are distributed across the 43 charts of the and as follows: In some cases, the already reflected the open/closed distinction with separate rhyme groups, while in others they were included in the same group. ==Thirty-six initials==