# Proto-Sino-Tibetan language

Proto-Sino-Tibetan (PST) is the linguistic reconstruction of the Sino-Tibetan proto-language and the common ancestor of all languages in it, including the Sinitic languages, the Tibetic languages, Yi, Bai, Burmese, Karen, Tangut, and Naga. Paul K. Benedict (1972) placed a particular emphasis on Old Chinese, Classical Tibetan, Jingpho, Written Burmese, Garo, and Mizo in his discussion of Proto-Sino-Tibetan.
While Proto-Sino-Tibetan is commonly considered to have two direct descendants, Proto-Sinitic and Proto-Tibeto-Burman, in recent years several scholars have argued that this was not well-substantiated, and have taken to calling the group "Trans-Himalayan". In this case, Proto-Tibeto-Burman may be considered as equivalent to Proto-Sino-Tibetan if Sinitic is indeed not the first branch to split from Proto-Sino-Tibetan.

## Features

Reconstructed features include prefixes such as the causative s-, the intransitive m-, the miscellaneous b-, d-, g-, and r-, suffixes -s, -t, and -n, and a set of conditioning factors that resulted in the development of tone in most languages of the family. The existence of such elaborate system of inflectional changes in Proto-Sino-Tibetan makes the language distinctive from some of its modern descendants, such as the Sinitic languages, which have mostly or completely become analytic.
Proto-Sino-Tibetan, like Old Chinese, also included numerous consonant clusters, and was not a tonal language.

## Phonology
### Benedict (1972)

The table below shows consonant phonemes reconstructed by Benedict.
| | Plosive | Plosive | Fricative | Fricative | Sonorant | Sonorant |
| | Voiceless | Voiced | Voiceless | Voiced | Nasal | Other |
| Labial | p | b | | | m | w |
| Dental | t | d | s | z | n | r |
| Palatal | c | | | ʒ | | y |
| Lateral | | | | | | l |
| Velar | k | g | h | | ŋ | |

### Peiros & Starostin (1996)

The reconstruction by Peiros & Starostin suggests a much more complex consonant inventory. The phonemes in brackets are reconstructions that are considered dubious.
| | Plosive/Affricate | Plosive/Affricate | Plosive/Affricate | Plosive/Affricate | Plosive/Affricate | Fricative | Fricative | Sonorant | Sonorant |
| | Unaspirated | Unaspirated | Unaspirated | Aspirated | Aspirated | | Fricative | Fricative | Sonorant | Sonorant |
| | Voiceless | Voiced | Voiced | Voiceless | Voiced | Voiceless | Voiced | Sonorant | Sonorant |
| | Voiceless | Oral | Nasal | Voiceless | Voiced | Voiceless | Voiced | Sonorant | Sonorant |
| Labial | p | b | m | pʰ | (bʰ) | | | w |
| Dental | t | d | n | tʰ | (dʰ) | | | r |
| Alveolar | c | ʒ | | cʰ | (ʒʰ) | s | | |
| Palatal | ć | ʒ́ | ń | ćʰ | ʒ́ʰ | ś | | y |
| Lateral | (ƛ) | | | | | | | l |
| Velar | k | g | ŋ | kʰ | (gʰ) | x | ɣ | |
| Uvular | (q) | (ɢ) | | (qʰ) | (ɢʰ) | (χ) | | |
| Laryngeal | ʔ | | | | | | | |

### Hill (2019)

The following tables show the reconstruction of Proto-Sino-Tibetan phonemes by Nathan Hill (2019).
| Consonants | Consonants | Labial | Coronal | Palatal | Velar | Labiovelar | Uvular | Labiouvular | Glottal |
| Nasal | Nasal | *m | *n | | *ŋ | *ŋʷ | | | |
| Plosive | voiced | *b | *d | | *g | | *ɢ | *ɢʷ | |
| Plosive | voiceless | *p | *t | | *k | *kʷ | *q | | *ʔ |
| Affricate | voiced | | *dz | | | | | | |
| Affricate | voiceless | | *ts | | | | | | |
| Fricatives | Fricatives | | *(s) | | | | | | |
| Approximant | Approximant | | *l | *j | | | | | |
| Rhotic | Rhotic | | *r | | | | | | |
* ↑ The sibilant correspondences are simply presented according to their proto-Burmish outcomes, as no patterns could be found by Hill.
* ↑ This consonant can only exist as a coda.
* ↑ This phonetic nature of this rhotic is unknown.
The consonants /p t k q ʔ m n ŋ l r j/ can take coda position, as well as the cluster /rl/. While Hill does not reconstruct /j/ as an initial consonant due to Baxter and Sagart's Old Chinese reconstruction lacking such a phoneme, he mentions that Jacques and Schuessler suggest a /j/ initial for some Old Chinese words due to potential Tibetan or Rgyalrongic cognates.
| Vowels | Front | Central | Back |
| Close | i | | u |
| Mid | e | ə | o |
| Open | | a | |
Hill also claims that his reconstruction is incomplete, as it does not account for Tibetic palatalization, proto-Burmish preglottalization, Sinitic aspirates, and the Sinitic type A and B distinction of syllables.

#### Sound correspondences

The sound correspondences cited by Hill (2019) are as follows. Hill bases his correspondences to Old Chinese off of the Baxter-Sagart reconstruction, and thus that reconstruction will be used in the following correspondence tables.

##### Initials

Note that many cognate sets with /p t k b d g/ initials between Old Chinese, Tibetan and Burmese agree in every phoneme in a given word except for whether an initial consonant is voiced or not. Jacques explains these discrepancies as at least partially triggered by pre-syllables that were lost or decayed on the way to Chinese, Tibetan and Burmese.
Expected initial correspondences in Hill (2019) :
| Proto-Sino-Tibetan | Old Chinese | Tibetan | Written Burmese |
| *p- | *p- | p- | p- |
| *t- | *t- | t- | t- |
| *k- | *k- | k- | k- |
| *kʷ- | *kʷ- | k- | ? |
| *b- | *b- | b- | p- |
| *d- | *d- | d- | t- |
| *g- | *g- | g- | g- |
| *q- | *q- | k(h)- | (lost) |
| *ɢ- | *ɢ- | g- | ? |
| *ɢʷ- | *ɢʷ- | g- | w- |
| *ts- | *ts- | ts(h)- | ch- |
| *dz- | *dz- | (d)z- | c- |

##### Vowels

Vowel correspondences of vowels in Hill (2019) :
| Proto-Sino-Tibetan | Old Chinese | Tibetan | Written Burmese |
| *a | *a | a o | a |
| *e | *e | e i a | a |
| *i | *i | i | i |
| *o | *o | o | wa |
| *u | *u | u | u o |
| *uw | *u | u | ui uiw |
| *ə | *ə | a | a |
| *əw | *o | u | u |
| *əj | *əj | a ~ e | i |
* ↑ After rounded dorsal consonants.
* ↑ Before velar consonants.
* ↑ Before dental or liquid consonants.
* ↑ Before velar, dental or liquid consonants. In Proto-Burmish, pre-velar *i (from *e and *i) were still both distinct from *a.
* ↑ o in Old Burmese.
* ↑ Before velars. Did not merge with inherited *o > Old Burmese o > Written Burmese wa.
* ↑ In Old Burmese.

##### Finals

Final correspondences according to Hill (2019) :
| Proto-Sino-Tibetan | Old Chinese | Tibetan | Written Burmese |
| *-p | *-p | -b | -p |
| *-t | *-t | -d | -t |
| *-k | *-k | -g | -k |
| *-kə | *-k | (lost) | (lost) |
| *-q | *-ʔ | -g | -k |
| *-ʔ | *-ʔ | (lost) | (lost) |
| *-m | *-m | -m | -m |
| *-n | *-n | -n | -n -ñ(ñ) |
| *-ŋ | *-ŋ | -ng | -ng |
| *-l | *-j | -l | (lost) |
| *-r | *-r | -r | (lost) |
| *-rl | *-r | -l | (lost) |
* ↑ Except after *a, where this final instead surfaces as -' (transliterated ḫ by Hill).
* ↑ After *e or *i.
* 1 2 Unless after *u; in this case the final surfaces as -y.

## Sound changes
### Final consonant changes

In Gong Huangcheng's reconstruction of the Proto-Sino-Tibetan language, the finals *-p, *-t, *-k, *-m, *-n, and *-ŋ in Proto-Sino-Tibetan remained in Proto-Sinitic and Proto-Tibeto-Burman. However, in Old Chinese, the finals *-k and *-ŋ that came after the close vowel *-i- underwent an irregular change of *-k＞*-t and *-ŋ ＞*-n. In Proto-Tibeto-Burman, *-kw and *-ŋw underwent a sound change to become *-k and *-ŋ respectively, while in Old Chinese those finals remained until Middle Chinese, where the finals underwent the same sound change.
Furthermore, in Proto-Tibeto-Burman, the finals *-g, *-gw, and *-d underwent the following changes:
* *-d＞*-y
* *-gw＞*-w
* *-g＞*-w when it follows the vowel *-u-
* *-g＞*-∅ when it follows the vowel *a and *-a-.

### Example of sound changes
#### Voiceless plosive finals

| | Proto-Sino-Tibetan | Old Chinese (Li Fang-Kuei) | Proto-Tibeto-Burman |
| *-p | *-jəp | 汲 *kjəp | *ka·p |
| *-p | *-jəp | 泣 *khrjəp | *krap |
| *-p | *-jəp | 立 *(g-)rjəp | *g-ryap |
| *-p | *-jap | 接 *tsjap | *tsyap |
| *-p | *-jup | 入 *njəp | *nup~ *nip |
| *-t | *-iat | 八 *priat | *b-r-gyat |
| *-t | *-iat | 殺 *r-siat | *g-sat |
| *-t | *-uat | 脫 *hluat | *g-lwat |
| *-t | *-jit | 一 *·jit | *it |
| *-k | *-ək | 翼 *lək | *lak |
| *-k | *-jək | 織 *tjək | *tak |
| *-k | *-jək | 息 *sjək | *sak |
| *-k | *-jək | 食 *N-ljək | *(m-)lyak |
| *-k | *-jək | 飼 *s-ljəks | *(s-)lyak |
| *-k | *-ik | 節 *tsik＞*tsit | *tsik |
| *-k | *-ik | 縊 *·iks, *·jiks | *ik |
| *-k | *-jik | 蝨 *srjik＞*srjit | *s-rik |
| *-k | *-juk | 曲 *khjuk | *guk~kuk |
| *-kw | *-əkw | 毒 *dəkw | *duk~*tuk |
| *-kw | *-jəkw | 腹 *phjəkw, *bjəkw | *pu·k~*buk |
| *-kw | *-jəkw | 六 *drjəkw | *d-ruk |

#### Nasal finals

| | Proto-Sino-Tibetan | Old Chinese (Li Fang-Kuei) | Proto-Tibeto-Burman |
| *-m | *-əm | 含 *gəm | *gam |
| *-m | *-əm | 頷 *gəm | *gam |
| *-m | *-jəm | 飲 *·jəmx | *am |
| *-m | *-jəm | 尋 *ljəm | *la[·]m |
| *-m | *-jim | 坅 *khjamx “pit” | *kim |
| *-m | *-um | 三 *səm | *g-sum |
| *-m | *-jum | 尋 *ljəm | *lum |
| *-n | *-an | 乾 *kan | *kan |
| *-n | *-jin | 辛 *sjin | *m-sin |
| *-ng | *-jəng | 夢 *mjəngs | *mang |
| *-ng | *-jəng | 蒸 *tjəng | *tang |
| *-ng | *-jang | 紡 *phjangx | *pang |
| *-ng | *-jang | 涼 *grjang | *grang |
| *-ng | *-jang | 迎 *ngrjang | *ngang |
| *-ng | *-ing | 盈 *bling | *bling~pling |
| *-ng | *-jing | 年 *ning＞*nin | *ning |
| *-ng | *-jing | 名 *mjing | *r-ming |
| *-ng | *-jing | 甥 *srjing | *sring |
| *-ng | *-jing | 薪 *sjing＞*sjin | *sing |
| *-ng | *-jing | 仁 *njing＞*njin | *s-ning |
| *-ngw | *-jəngw | 躬 *kjəngw | *gung |

#### Voiced plosive finals

| | Proto-Sino-Tibetan | Old Chinese (Li Fang-Kuei) | Proto-Tibeto-Burman |
| *-b | *-əb | 柔 *njəb＞*njəgw | *nəw |
| *-d | *-əd | 𤈦 *smjədx | *məy |
| *-d | *-ad | 簸 *padx/s | *pwa·y |
| *-d | *-ad | 太 *tads | *tay |
| *-d | *-ad | 蜾 *kwadx | *kwa·y |
| *-d | *-ad | 我 *ngadx | *ngay |
| *-d | *-ad | 移 *lad | *lay |
| *-d | *-id | 四 *sjids | *b-liy |
| *-d | *-jid | 妣 *pjidx | *piy |
| *-d | *-jid | 畀 *sbjids | *biy |
| *-d | *-jid | 几 *krjidx | *kriy |
| *-d | *-jid | 屎 *skhljidx | *kliy |
| *-d | *-jid | 死 *sjidx | *siy |
| *-g | *-əg | 母 *məgx | *ma |
| *-g | *-jəg | 負 *bjəgx | *ba, *bak |
| *-g | *-jəg | 子 *tsjəgx | *tsa |
| *-g | *-jəg | 慈 *dzjəg | *m-dza |
| *-g | *-jəg | 孳 *dzjəgs | *za |
| *-g | *-jəg | 耳 *njəgx | *r-na~*g-na |
| *-g | *-jəg | 牛 *ngwjəg | *ngwa |
| *-g | *-ag | 補 *pagx | *pa |
| *-g | *-ag | 苦 *khagx | *ka |
| *-g | *-ag | 吾 *ngag | *nga |
| *-g | *-ag | 五 *ngagx | *l-nga~*b-nga |
| *-g | *-ag | 狐 *gwag | *gwa |
| *-g | *-jag | 斧 *pjagx | *r-pwa |
| *-g | *-jag | 夫 *pjag | *(p)wa |
| *-g | *-jag | 父 *bjagx | *pa |
| *-g | *-jag | 無 *mjag | *ma |
| *-g | *-jag | 魚 *ngjag | *ngya |
| *-g | *-jag | 咀 *dzjag | *dza |
| *-g | *-jag | 汝 *njagx | *na |
| *-g | *-ug | 口 *khugx | *kuw |
| *-g | *-ug | 寇 *khugs | *r-kuw |
| *-g | *-jug | 霧 *m(r)jugs | *(r-)muw |
| *-g | *-jug | 軀 *khjug | *(s-)kuw |
| *-g | *-jug | 乳 *njugx | *nuw |
| *-gw | *-əgw | 寶 *pəgwx | *puw |
| *-gw | *-əgw | 抱 *bəgwx | *buw |
| *-gw | *-jəgw | 鳩 *kjəgw | *kuw |
| *-gw | *-jəgw | 九 *kjəgwx | *d-kuw |
| *-gw | *-jəgw | 舅 *gjəgwx | *kuw |
| *-gw | *-agw | 豪 *gagw | *m/s-gaw |
| *-gw | *-agw | 號 *gagws | *gaw |
| *-gw | *-agw | 熬 *ngagw | *r-ngaw |
| *-gw | *-agw | 臊 *sagw | *sa·w |
| *-gw | *-jagw | 飄/漂 *phjagw | *pyaw |

#### Liquid finals

| | Proto-Sino-Tibetan | Old Chinese (Li Fang-Kuei) | Proto-Tibeto-Burman |
| *-l | *-al | 肝 *kan | *m-kal |
| *-l | *-ul | 本 *pən | *bul~*pul |
| *-l | *-jul | 銀 *ngjən | *(d)-ngul |
| *-l | *-jul | 閩 *mjən | *s-brul |
| *-l | *-jal | 疲 *brjal | *bal |
| *-l | *-il | 洒 *silx | *(m-)s(y)il |
| *-r | *-ar | 播 *s-bars | *bwar |
| *-r | *-ar | 皤 *bar, *par | *pwa:r |
| *-r | *-jar | 販 *pjans | *par |
| *-r | *-jar | 鮮 *sjan | *sar |
| *-r | *-uar | 酸 *suan | *swa·r |
| *-r | *-jur | 飛 *pjər | *pur~*pir |

## Vocabulary

Words which do not have reliable Sinitic parallels are accompanied by a (TB).

### Social terms

| English | Reconstruction by | Reconstruction by | Old Chinese (Baxter-Sagart) |
| English | I. Peiros & S. Starostin | J. Matisoff | Old Chinese (Baxter-Sagart) |
| Person (in general) | *mĭ | *mi | 民 *mi[ŋ] |
| Male | *pă | *pʷa | 父 *p(r)aʔ |
| Female | *mǝw | *mow | 母 *mˤoʔ (or məʔ) |
| Name (of a person) | *miǝŋ | *miŋ | 名 *C.meŋ |

### Natural phenomena

| English | Reconstruction by | Reconstruction by | Old Chinese (Baxter-Sagart) |
| English | I. Peiros & S. Starostin | J. Matisoff | Old Chinese (Baxter-Sagart) |
| Earth | *ƛăy | *ley ~ *lǝy | 地 *[l]ˤej-s |
| Stone | *ƛɨāŋ ~ *ƛɨāk | *luŋ ~ *luk | 琭 *[r]ˤok |
| Sand | *srāy | *sa | 沙 *sˤraj |
| Fire | *mēyH | *mey | 火 *[qʷʰ]ˤəjʔ |
| Smoke | *gʰiw | *kǝw | 熏 *qʰu[n] |
| Water | *tujʔ | *t(w)i(y) | 水 *s.turʔ |
| Rain | *(r-)qʰʷăH | *rwa ~ *wa | 雨 *C.ɢʷ(r)aʔ |
| Sun | *nĭy | *nǝy | 日 *C.nik |
| Moon (TB) | *(s-)lăH | *la | N/A |
| Star | *(s-)q(ʰ)ār | *kar | 扈 *m-qˤaʔ |
| Night | *yăH | *ya | 夜 *[ɢ]Ak-s |
| Tree | *sĭŋ | *siŋ ~ *sik | 薪 *[s]i[n] |
| Leaf | *lăp | *lap | 葉 *l[a]p |
| Plant root | *bʰūl | *bul ~ *pul | 本 *C.pˤə[n]ʔ |
* ↑ See also the dialectal 𤈦 /*m̥əjʔ/ and 燬 /*m̥ajʔ/.
* ↑ Chinese 月 /*[ŋ]ʷat/ is a descendant of another PST word, *s-ŋʷ(j)a-t.
* ↑ Unclear. The more common word is 星 /*s-tsʰˤeŋ/, which is possibly related to 清 /*tsʰeŋ/, in turn from PST *(t)s(j)aŋ.

### Qualitative features of an object

| English | Reconstruction by | Reconstruction by | Old Chinese (Baxter-Sagart) |
| English | I. Peiros & S. Starostin | J. Matisoff | Old Chinese (Baxter-Sagart) |
| Black, dark (TB) | *nǝk | *nak | 黑 *m̥ˤək |
| White | wār | *hwār | 皤 *[b]ˤar |
| Big | *tayH | *tay | 大 *lˤa[t]-s |
| Cold | *(k-)răŋ ~ *(k-)răk | *glak ~ *glaŋ ~ *graŋ | 涼 *C.raŋ |
| Warm | *lɨm | *lim ~ *lum | 融 *luŋ |
| Long (TB) | *rĭŋ | *riŋ | N/A |
| New | *cʰăr | *sar | 鮮 *s[a]r |
* ↑ It is possible that *s-nak is a descendant of *s-maŋ ~ s-mak (whence OC /*m̥ˤək/).
* ↑ The more commonly used 白 /*bˤrak/ might be a derivation of it.

### Verb stems

| English | Reconstruction by | Reconstruction by | Old Chinese (Baxter-Sagart) |
| English | I. Peiros & S. Starostin | J. Matisoff | Old Chinese (Baxter-Sagart) |
| To eat | *ʒʰa | *dzya | 咀 *dzaɁ |
| To drink | *dʰɨn ~ *dʰɨŋ | *daŋ ~ *doŋ | |
| To bite/chew | *wā | *wa | |
| To die | *sĭy(H) | *sǝy | 死 *sijʔ |
| To know, to think | *siǝH | *syey | 悉 *[s]i[t] |
| To hear (TB) | *tʰa(s) | *ta | N/A |
| To sleep | *mĭyH | *mwǝy | 寐 *mi[t]-s |
| To stand | *ryǝp | *r(y)ap | 立 *k.rәp |
| To sit | *tūŋ ~ *tūk | *duŋ ~ *duk ~ *tuŋ ~ *tuk | 住 *dro(ʔ)-s |
| Give | *pĭy | *bǝy | 畀 *pi[k]‑s |

### Numbers

| Number | Reconstruction by | Reconstruction by | Old Chinese (Baxter-Sagart) | Old Tibetan | Old Burmese |
| Number | I. Peiros & S. Starostin | J. Matisoff | Old Chinese (Baxter-Sagart) | Old Tibetan | Old Burmese |
| 1 | *dyiǝk | *dik ~ *t(y)ik ~ *t(y)ak | 一 *ʔi[t], 隻 *tek | gcig | ac, tac |
| 2 | *nĭy | *ni | 二 *ni[j]-s | gnyis | nhac < *nhik |
| 3 | *sɨm | *sum | 三 *s.rum | gsum | sumḥ |
| 4 | *lĭy | *lǝy | 四 *s.li[j]-s | bzhi | liy |
| 5 | *ŋāH | *ŋa | 五 *C.ŋˤaʔ | lnga | ṅāḥ |
| 6 | *rŭk | *ruk | 六 *k.ruk | drug | khrok < *khruk |
| 7 | *(s-)nĭt | *ni | 七 *[tsʰ]i[t] | N/A | khu-nac |
| 8 | *ryēt | *gyat ~ *ryat ~ *rit | 八 *pˤret | brgyad | rhac < rhyat |
| 9 | *kwɨH | *gǝw ~ *kǝw | 九 *[k]uʔ | dgu | kuiḥ |
| 10 | *k(ʰ)ĭp | *g(y)ip | 十 *t.[g]әp | N/A | kip |
| 100 | *(p-)ryā | *gya | 百 *pˤrak | brgya | ryā |
* ↑ Tibetan bdun has unknown origins, likely used to avoid confusion with the similar-sounding "two".
* ↑ Tibetan bcu is a descendant of another PST root, *tsjaj.
* 1 2 3 4 5 For Old Chinese notations in the Baxter–Sagart system: Parentheses "" indicate uncertain presence; Square brackets "" indicate uncertain identity, e.g. *[t] as coda may in fact be *-t or *-p; Angle brackets "<>" indicate infix; Hyphen "-" indicates morpheme boundary; Period "." indicates syllable boundary.