Proto-Tai is the reconstructed proto-language (common ancestor) of all the Tai languages, including modern Lao, Shan, Tai Lü, Tai Dam, Ahom, Northern Thai, Standard Thai, Bouyei, and Zhuang. The Proto-Tai language is not directly attested by any surviving texts, but has been reconstructed using the comparative method.
It was reconstructed in 1977 by Li Fang-KueiLi, Fang-Kuei. (1977). A handbook of comparative Tai. Manoa: University Press of Hawaii. and by Pittayawat Pittayaporn in 2009.Pittayaporn, Pittayawat. (2009a). The Phonology of Proto-Tai (Doctoral dissertation). Department of Linguistics, Cornell University.
Phonology
Consonants The following table shows the consonants of Proto-Tai according to Li Fang-Kuei's A Handbook of Comparative Tai (1977), considered the standard reference in the field. Li does not indicate the exact quality of the consonants denoted here as [, and ], which are indicated in his work as [č, čh, ž] and described merely as palatal affricate consonants.
+ Proto-Tai consonants (Li 1977) Type Labial Alveolar Palatal Velar Glottal StopVoiceless Voiceless aspirated Voiced Glottalized FricativeVoiceless Voiced NasalVoiceless Voiced Liquidor semivowelVoiceless Voiced
The table below lists the consonantal phonemes of Pittayawat Pittayaporn's reconstruction of Proto-Tai.: p. 70 Some of the differences are simply different interpretations of Li's consonants: the palatal consonants are interpreted as stops, rather than affricates, and the glottalized consonants are described using symbols for implosive consonants. However, Pittayaporn's Proto-Tai reconstruction has a number of real differences from Li: Pittayaporn does not allow for aspirated consonants, which he reconstructs as secondary developments in Southwestern Tai languages (after Proto-Tai split up into different languages). He also reconstructs a contrastive series of uvular consonants, namely */q/, */ɢ/, and */χ/. No modern dialect preserves a distinct series of uvular consonants. Pittayaporn's reconstruction of the sounds is based on irregular correspondences in differing modern Tai dialects among the sounds /kʰ/, /x/ and /h/, in particular in the Phuan language and the Kapong dialect of the Phu Thai language. The distinction between /kʰ/ and /x/ can be reconstructed from the Tai Dón language. However, words with /x/ in Tai Dón show three different types of correspondences in Phuan and Kapong Phu Thai: some have /kʰ/ in both languages, some have /h/ in both, and some have /kʰ/ in Phuan but /h/ in Kapong Phu Thai. Pittayaporn reconstructs the correspondence classes as reflecting Proto-Tai /x/, and /q/, respectively.Pittayaporn, Pittayawat (2009b). Proto-Southwestern-Tai Revised: A New Reconstruction. Journal of the Southeast Asian Linguistics Society, 2, 121–144.
There is a total of 33–36 consonants, 10–11 consonantal syllable codas and 25–26 tautosyllabic consonant clusters.
+ Proto-Tai consonants (Pittayaporn 2009) Type Labial Alveolar Palatal Velar Uvular Glottal StopVoiceless Voiced Glottalized FricativeVoiceless () Voiced () NasalVoiceless ()Voiced Liquidor semivowelVoiceless Voiced
Tai languages have many fewer possible consonants in coda position than in initial position. Li (and most other researchers) construct a Proto-Tai coda inventory that is identical with the system in modern Thai.
+ Proto-Tai consonantal syllabic codas (Li 1977) Type Labial Alveolar Palatal Velar Glottal Stop -p -t -k -ʔ Nasal -m -n -ŋ semivowel -w -j
Pittayaporn's Proto-Tai reconstructed consonantal syllable codas also include *-l, *-c, and possibly *-ɲ, which are not included in most prior reconstructions of Proto-Tai.: p. 193 Below is the consonantal syllabic coda inventory:
+ Proto-Tai consonantal syllabic codas (Pittayaporn 2009) Type Labial Alveolar Palatal Velar Stop -p -t -c -k Nasal -m -n (-ɲ) -ŋ Liquid or semivowel -w -l -j
Norquest (2021) reconstructs the voiceless retroflex stop /ʈ/ for Proto-Tai. Examples of voiceless retroflex stops in Proto-Tai:
Gloss proto-Tai p-North Tai p-Central Tai p-Southwest Tai ‘lift’ *ʈaːm *r̥aːm *tʰraːm *haːm ‘head louse’ *ʈaw *r̥aw *tʰraw *haw ‘to see’ *ʈaȵ *r̥aȵ *tʰran *hen ‘eye’ *p-ʈaː *p-ʈaː *p-tʰraː *taː ‘die’ *p-ʈaːj *p-ʈaːj *p-tʰraːj *taːj ‘grasshopper’ *p-ʈak *p-ʈak *p-tʰrak *tak
Norquest (2021) also reconstructs a series of breathy voiced initials (*bʱ, *dʱ, *ɡʱ, *ɢʱ) for Proto-Tai. Examples of breathy voiced initials in Proto-Tai:
Gloss proto-Tai p-North Tai p-Central Tai p-Southwest Tai ‘person’ *bʱuːʔ *buːʔ *pʰuːʔ *pʰuːʔ ‘bowl’ *dʱuəjʔ *duəjʔ *tʰuəjʔ *tʰuəjʔ ‘eggplant’ *ɡʱɯə *gɯə *kʰɯə *kʰɯə ‘rice’ *ɢʱawʔ *ɣawʔ *kʰawʔ *kʰawʔ
Some sound correspondences among Proto-Tai, Proto-Northern Tai, and Proto-Southern Tai (i.e., the ancestor of the Central and Southwestern Tai languages) uvular initials given in Ostapirat (2023) are as follows.
p-Tai p-Northern Tai p-Southern Tai *q- *k- *x- *ɢ- *ɣ- *g- *ɢʰ- *ɣ- *kʰ-
Initial velar correspondences, on the other hand, are identical.
p-Tai p-Northern Tai p-Southern Tai *x- *x- *x- *ɣ- *ɣ- *ɣ-
Consonant clusters Li (1977) reconstructs the following initial clusters:
+ Proto-Tai consonant clusters (Li 1977) Type Labial Alveolar Velar Unvoiced Stop pr-, pl- tr-, tl- kr-, kl-, kw- Aspirated unvoiced stop pʰr-, pʰl- tʰr-, tʰl- kʰr-, kʰl-, kʰw- Voiced Stop br-, bl- dr-, dl- ɡr-, ɡl-, ɡw- Implosive ʔbr-, ʔbl- ʔdr-, ʔdl- Voiceless Fricative fr- xr-, xw- Voiced Fricative vr-, vl- Nasal mr-, ml- nr-, nl- ŋr-, ŋl-, ŋw- Liquid
Pittayaporn (2009) reconstructs two types of complex onsets for Proto-Tai:
Tautosyllabic clusters – considered one syllable. Sesquisyllabic clusters – "one-and-a-half" syllables. ("Sesquisyllabic" is a term coined by James Matisoff.) However, sesquisyllabic clusters are not attested in any modern Tai language.
Tautosyllabic consonant clusters from Pittayaporn: p. 139 are given below, some of which have the medials *-r-, *-l-, and *-w-.
+ Proto-Tai consonant clusters (Pittayaporn 2009) Type Labial Alveolar Palatal Velar Uvular Unvoiced Stop pr-, pl-, pw- tr-, tw- cr- kr-, kl-, kw- qr-, qw- Implosive br-, bl-, bw- ɡr-, (ɡl-) ɢw- Fricative sw- xw-, ɣw- Nasal ʰmw- nw- ɲw- ŋw- Liquid ʰrw-, rw-
Pittayaporn's Proto-Tai reconstruction also has sesquisyllabic consonant clusters. Michel Ferlus (1990) had also previously proposed sesquisyllables for Proto-Thai-Yay.Ferlus, Michel (1990). Remarques sur le Consonnantisme du Proto-Thai-yay. Paper presented at the 23rd International Conference on Sino-Tibetan Languages and Linguistics. University of Texas at Arlington, Oct. 5–7. The larger Tai-Kadai family is reconstructed with disyllabic words that ultimately collapsed to monosyllabic words in the modern Tai languages. However, irregular correspondences among certain words (especially in the minority non-Southwestern-Tai languages) suggest to Pittayaporn that Proto-Tai had only reached the sesquisyllabic stage (with a main monosyllable and optional preceding minor syllable). The subsequent reduction to monosyllables occurred independently in different branches, with the resulting apparent irregularities in synchronic languages reflecting Proto-Tai sesquisyllables.
Examples of sesquisyllables include:
Voiceless stop + voiceless stop (*C̥.C̥-) *p.t- *k.t- *p.q- *q.p-
Voiceless obstruent + voiced stop (*C̥.C̬-) *C̥.b- *C̥.d-
Voiced obstruent + voiceless stop (*C̬.C̥-) *C̬.t- *C̬.k- *C̬.q-
Voiceless stops + liquids/glides (*C̥.r-) *k.r- *p.r- *C̥.w-
Voiced consonant + liquid/glide *m.l- *C̬ .r- *C̬ .l-
Clusters with non-initial nasals *t.n- *C̬ .n-
Other clusters include *r.t-, *t.h-, *q.s-, *m.p-, *s.c-, *z.ɟ-, *g.r-, *m.n-; *gm̩.r-, *ɟm̩ .r-, *c.pl-, *g.lw-; etc.
Vowels Below are Proto-Tai vowels from Pittayaporn.: p. 192 Unlike Li's system, Pittayaporn's system has vowel length contrast. There is a total of 7 vowels with length contrast and 5 diphthongs.
+ Proto-Tai vowels (Pittayaporn 2009) TypeFrontBackunroundedunroundedrounded short long short long short longCloseMidOpen
The diphthongs from Pittayaporn (2009) are: Rising: */iə/, */ɯə/, */uə/ Falling: */ɤɰ/, */aɰ/
Tones
Proto-Tai had three contrasting tones on syllables ending with sonorant finals ("live syllables"), and no tone contrast on syllables with obstruent finals ("dead syllables"). This is very similar to the situation in Middle Chinese. For convenience in tracking historical outcomes, Proto-Tai is usually described as having four tones, namely *A, *B, *C, and *D, where *D is a non-phonemic tone automatically assumed by all dead syllables. These tones can be further split into a voiceless (*A1 , *B1 , *C1 , *D1 ) and voiced (*A2 , *B2 , *C2 , *D2 ) series. The *D tone can also be split into the *DS (short vowel) and *DL (long vowel) tones. With voicing contrast, these would be *DS1 , *DS2 , *DL1 , and *DL2 .Liao, Han-Bo. (2016). Tonal Development of Tai Languages (master's thesis). Payap University, Chiang Mai, Thailand. Other Kra–Dai languages are transcribed with analogous conventions.
+ Proto-Tai tone notation Type of voicing *A *B *C *D Voiceless series (Letter notation) A1 B1 C1 D1 Voiceless series (Numerical notation) 1 3 5 7 Voiced series (Letter notation) A2 B2 C2 D2 Voiced series (Numerical notation) 2 4 6 8
The following table of the phonetic characteristics of Proto-Tai tones was adapted from Pittayaporn.: p. 271 Note that *B and *D are phonetically similar.
+ Proto-Tai tonal characteristics (Pittayaporn 2009) Type *A *B *C *D Type of final sonorant sonorant sonorant obstruent Pitch height mid low high low Contour level low rising high falling low rising Vowel duration – long short – Voice quality modal creaky glottal constriction –
Proto-Tai tones take on various tone values and contours in modern Tai languages. These tonal splits are determined by the following conditions: "Friction sounds": Aspirated onset, voiceless fricative, voiceless sonorant Unaspirated onset (voiceless) Glottalized/implosive onset (voiceless) Voiced onset
In addition, William J. Gedney developed a "tone-box" method to help determine historical tonal splits and mergers in modern Tai languages. There is a total of 20 possible slots in what is known as the Gedney's Tone Box.Gedney, William J. (1972). A Checklist for Determining Tones in Tai Dialects. In M. E. Smith (Ed.). Studies in Linguistics: In Honor of George L. Trager (pp. 423–437). Mouton.Owen, R. W. (2012). A tonal analysis of contemporary Tai Khuen varieties. Journal of the Southeast Asian Linguistics Society (JSEALS), 5, 12–31.Manson, Ken. (2009). Prolegomena to Reconstructing Proto-Karen. La Trobe Papers in Linguistics, 12. Available at Morey, Stephen. (2014). Studying tones in North East India: Tai, Singpho and Tangsa. Language Documentation & Conservation, 8, 637–671.
+ Gedney Box template Type *A *B *C *DS *DL Voiceless (friction) A1 B1 C1 DS1 DL1 Voiceless (unaspirated) A1 B1 C1 DS1 DL1 Voiceless (glottalized) A1 B1 C1 DS1 DL1 Voiced A2 B2 C2 DS2 DL2
Proto-Tai tones correspond regularly to Middle Chinese tones. (Note that Old Chinese did not have tones.) The following tonal correspondences are from Luo (2008). Note that Proto-Tai tone *B corresponds to Middle Chinese tone C, and vice versa.
+ Sinitic–Tai tonal correspondences Proto-TaiTone Notes(Written Thai orthography) Middle Chinese Tone Chinese name Notes(Middle Chinese) *A Unmarked A 平 Level (Even) Unmarked *B Marked by -่ (mai ek) C 去 Departing Marked by -H in Baxter's notation (mai tho), historically perhaps from [-s] later [-h] *C Marked by -้ (mai tho) B 上 Rising Marked by -X in Baxter's notation, historically perhaps from [-ʔ] *D Unmarked or marked by -๊ (mai tri) D 入 Entering Marked by -p, -t, -k