Proto-Tai


Proto-Tai is the reconstructed proto-language 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-Kuei and by Pittayawat Pittayaporn in 2009.

Phonology

Consonants

The following table shows the consonants of Proto-Tai according to Li Fang-Kuei's A Handbook of Comparative Tai, considered the standard reference in the field. Li does not indicate the exact quality of the consonants denoted here as , which are indicated in his work as and described merely as palatal affricate consonants.
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:
  1. Pittayaporn does not allow for aspirated consonants, which he reconstructs as secondary developments in Southwestern Tai languages.
  2. 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.
There is a total of 33-36 consonants, 10-11 consonantal syllable codas and 25-26 tautosyllabic consonant clusters.
Tai languages have many fewer possible consonants in coda position than in initial position. Li construct a Proto-Tai coda inventory that is identical with the system in modern Thai.
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:

Consonant clusters

Li reconstructs the following initial clusters:
Pittayaporn reconstructs two types of complex onsets for Proto-Tai:
  1. Tautosyllabic clusters – considered one syllable.
  2. Sesquisyllabic clusters – "one-and-a-half" syllables. 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-.
Pittayaporn's Proto-Tai reconstruction also has sesquisyllabic consonant clusters. Michel Ferlus had also previously proposed sesquisyllables for Proto-Thai-Yay. 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 suggest to Pittayaporn that Proto-Tai had only reached the sesquisyllabic stage. 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
;Voiceless obstruent + voiced stop
;Voiced obstruent + voiceless stop
;Voiceless stops + liquids/glides
;Voiced consonant + liquid/glide
;Clusters with non-initial nasals
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.
The diphthongs from Pittayaporn are:
Proto-Tai had three contrasting tones on syllables ending with sonorant finals, and no tone contrast on syllables with obstruent finals. 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 and voiced series. The *D tone can also be split into the *DS and *DL tones. With voicing contrast, these would be *DS1 , *DS2 , *DL1 , and *DL2 . Other Kra–Dai languages are transcribed with analogous conventions.
Type of voicing*A*B*C*D
Voiceless series
A1B1C1D1
Voiceless series
1357
Voiced series
A2B2C2D2
Voiced series
2468

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.
*A*B*C*D
Type of finalsonorantsonorantsonorantobstruent
Pitch heightmidlowhighlow
Contourlevellow risinghigh fallinglow rising
Vowel duration–longshort–
Voice qualitymodalcreakyglottal
constriction		–

Proto-Tai tones take on various tone values and contours in modern Tai languages. These tonal splits are determined by the following conditions:
  1. "Friction sounds": Aspirated onset, voiceless fricative, voiceless sonorant
  2. Unaspirated onset
  3. Glottalized/implosive onset
  4. 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.
*A*B*C*DS*DL
Voiceless
A1B1C1DS1DL1
Voiceless
A1B1C1DS1DL1
Voiceless
A1B1C1DS1DL1
VoicedA2B2C2DS2DL2

Proto-Tai tones correspond regularly to Middle Chinese tones. The following tonal correspondences are from Luo. Note that Proto-Tai tone *B corresponds to Middle Chinese tone C, and vice versa.
Proto-Tai
Tone		Notes
Middle Chinese
Tone		Chinese nameNotes
*AUnmarkedA平 Level Unmarked
*BMarked by -' C去 DepartingMarked by -h
*CMarked by -้ B上 RisingMarked by -x
*DUnmarkedD入 EnteringMarked by -p, -t, -k

Gedney also included a list of diagnostic words to determine tonal values, splits, and mergers for particular Tai languages. At least three diagnostic words are needed for each cell of the Gedney Box. The diagnostic words preceding the semicolons are from Gedney, and the ones following the semicolons are from Somsonge and Jackson, et al.. Standard Thai words are given below, with italicised transliterations.
*A*B*C*DS*DL
1: Voiceless
huu หู ear,
khaa ขา leg,
hua หัว head;
sɔɔŋ สอง two,
maa หมา dog		khay ไข่ egg,
phaa ผ่า to split,
khaw เข่า knee;
may ใหม่ new,
sii สี่ four		khaaw ข้าว rice,
sɨa เสื้อ shirt,
khaa ฆ่า to kill,
khay ไข้ fever,
haa ห้า five;
thuay ถ้วย cup,
mɔɔ หม้อ pot,
naa หน้า face,
to wait		mat หมัด flea,
suk สุก cooked/ripe,
phak ผัก vegetable;
hok หก six,
sip สิบ ten		khaat ขาด broken/torn,
ŋɨak เหงือก gums,
haap หาบ to carry on a shoulder pole;
khuat ขวด bottle,
phuuk ผูก to tie,
sɔɔk ศอก elbow,
khɛɛk แขก guest,
fruit
2: Voiceless
pii ปี year,
taa ตา eye,
kin กิน to eat;
kaa กา teapot,
plaa ปลา fish		paa ป่า forest,
kay ไก่ chicken,
kɛɛ แก่ old;
taw เต่า turtle,
paw เป่า to blow,
pii ปี flute,
short 		paa ป้า aunt,
klaa กล้า rice seedlings,
tom ต้ม to boil;
kaw เก้า nine,
klay ใกล้ near,
short 		kop กบ frog,
tap ตับ liver,
cep เจ็บ to hurt;
pet เป็ด duck,
tok ตก to fall/drop		pɔɔt ปอด lung,
piik ปีก wing,
tɔɔk ตอก to pound;
pɛɛt แปด eight,
paak ปาก mouth,
taak ตาก to dry in the sun,
to embrace
3: Voiceless
bin บิน to fly,
dɛɛŋ แดง red,
daaw ดาว star;
bay ใบ leaf,
nose		baa บ่า shoulder,
baaw บ่าว young man,
daa ด่า to scold;
ʔim อิ่ม full,
spring		baan บ้าน village,
baa บ้า crazy,
ʔaa อ้า to open ;
ʔɔy อ้อย sugarcane,
daam ด้าม handle,
daay ด้าย string		bet เบ็ด fishhook,
dip ดิบ raw/unripe,
ʔok อก chest;
dɨk ดึก late,
to extinguish		dɛɛt แดด sunshine,
ʔaap อาบ to bathe,
dɔɔk ดอก flower;
ʔɔɔk ออก exit
4: Voicedmɨɨ มือ hand,
khwaay ควาย water buffalo,
naa นา ricefield;
ŋuu งู snake,
house		phii พี่ older sibling,
phɔɔ พ่อ father,
ray ไร่ dry field;
naŋ นั่ง to sit,
lɨay เลื่อย to saw,
ashes,
urine,
beard		nam น้ำ water,
nɔɔŋ น้อง younger sibling,
may ไม้ wood,
maa ม้า horse;
lin ลิ้น tongue,
thɔɔŋ ท้อง belly		nok นก bird,
mat มัด to tie up,
lak ลัก to steal;
sak ซัก to wash,
mot มด ant,
lep เล็บ nail		miit มีด knife,
luuk ลูก child,
lɨat เลือด blood,
nɔɔk นอก outside;
chɨak เชือก rope,
raak ราก root,
nasal mucus,
to pull

Note that the diagnostic words listed above cannot all be used for other Tai-Kadai branches such as Kam–Sui, since tones in other branches may differ. The table below illustrates these differences among Tai and Kam–Sui.
GlossTaiKam–Sui
pigA1B1
dogA1A1
ratA1C1
ricefieldA2 B1
tongueA2 A2

Proto-Southern Kra-Dai

In 2007, Peter K. Norquest undertook a preliminary reconstruction of Proto-Southern Kra-Dai, which is ancestral to the Hlai languages, Ong Be language, and Tai languages. There are 28 consonants, 5-7 vowels, 9 closed rimes, and at least 1 diphthong, *ɯa.
Proto-Southern Kra-Dai medial consonants also include:
Proto-Southern Kra-Dai also includes the diphthong *ɯa.

Syllable structure

Unlike its modern-day monosyllabic descendants, Proto-Tai was a sesquisyllabic language. Below are some possible Proto-Tai syllable shapes from Pittayaporn.: p. 64
Open syllableClosed syllable
Monosyllable*CVT*CVCT
Sesquisyllable*C.CVT*C.CVCT

Legend:
During the evolution from Proto-Tai to modern Tai languages, monosyllabification involved a series of five steps.: p. 181
  1. Weakening
  2. Implosivization
  3. Metathesis
  4. Assimilation
  5. Simplification

    Morphology

suggests that the Proto-Tai language was fusional in its morphology because of related sets of words among the language's descendants that appear to be related through ablaut.

Syntax

Proto-Tai had a SVO word order like Chinese and almost all modern Tai languages. Its syntax was heavily influenced by Chinese.

Internal classification