(this is very old)

Before we can describe the grammar of Rau, we first must account for the ablaut patterns. So! The historical phonology of Rau.

The development of Continental Hathic from Gehui is somewhat obscure, since little lexical material was preserved. But some general developments can be stated:

- ur > ər; after this, rhoticity is lost, but turns adjacent alveolars into retroflexes (ɭ merges into the pre-existing retroflex flap)
- ɛ ɔ ɨ generally become a o ə; however, after palatals, ɛ ɨ instead become e i (and /ij/ sequences are simplified)
- a > e between palatals
- a > o before velarized labials
- bilabial clicks become dental or palatal clicks
- vowel pharyngealization, already basically a part of an overarching suprasegmental of retraction, is lost; in open syllables, it ejects a glottal stop, but in closed ones, this is without compensation
- the palatalized/velarized labial contrast is lost, except in the fricatives
- the implosives ɓ ɗ ʄ become ʔm ʔl ʔj respectively; however, this glottal is lost except before a vowel in compounds
- ħ > h; h > 0 syllable-finally
- l > dl, ʎ > l
- tɬ dl vary with kɬ gl - the former adjacent to front vowels, the latter otherwise
- there is a general but incomplete tendency toward click loss in unstressed grammatical words; this creates splits, for example between the abstract article and the relativizer

This leaves an inventory of:
/pʰ p b tʰ t d ʈʰ ʈ ɖ cʰ c ɟ kʰ k g ʔ/
/f s ʂ h/
/ʍ w ɕ j x ɣ tɬ dl/
/l ɭ/
/m n ɳ ɲ ŋ/
/a e ə o i u aː eː əː oː iː uː/

The prototypical root shape at this stage is still CVC. Fossilized compounds of the underlying form /CV1C-CV2.../ still eject an epenthetic copy of V1. Another relevant development is that the morpheme -lə - I at one point found natlang precedent for this, complete with a linguistically correct term for its function, but I've completely forgotten what it was - becomes -u. This change in syllable shape will be important later.

The ancestor of Rau, and of most Continental Hathic languages, simplifies further:
- Retroflexes cause diphthongization of following /i i:/ to /əj ə:j/ and then merge with alveolars, except ɭ > r
- schwa > a
- w > 0 syllable-finally
- long vowels shorten in unstressed syllables; short vowels lengthen in stressed open syllables

At this stage, the system of juncture begins to develop. There are five degrees of juncture:
- open juncture, or absence of juncture, which produces no effects
- semi-close juncture, which triggers loss of vowel length
- inherited juncture, which triggers the excrescence of a preceding vowel to avoid the creation of a CC sequence
- close juncture, which triggers loss of vowel length and voicing of unstressed /p t c k ʍ ɕ x tɬ/ to /b d ɟ g w j ɣ dl/
- clitic juncture, which triggers voicing and reduction of the vowel to an unstressed schwa <ᵊ>, which is then lost word-finally

On top of that, there is also the question of stress reduction. There are three degrees of stress: primary, secondary, and unstressed. Each junctural relation affects the stress of the conjoined words: whether stress is lost altogether,

Inherited juncture is used in certain fossilized compounds, but productively only in the system of inalienable possession. There are certain nouns that must be possessed - for example:

g|okɬ 'head (poss.)' + -yeɲ '1SG.POSS' > g|ókɬoyeɲ 'my head'

This is the only use of inherited juncture.

Semi-close juncture is used for most compounds, although some may shift to close juncture.

Close juncture is used for

Clitic juncture is used for pronominal clitics on the verb:
be: 'eat' + ka- '1SG.SUBJ' > gᵊbe: 'I eat...'
be: 'eat' + -ɲa 'DEF.animal' > be:ɲ '...eats the fish'

It's also used for the accusative case marker; other cases, however, take close juncture. Note that incorporation is generally preferred to case; there are complex discursive things that are relevant here. The poetic register does not have case.

- K > Q / _a(:) _o(:), e e: o o: > a a: a a:

The Rau Vowel Shift

  a  ə  i  u  a:  ə:  i: u:
B ɔ  ə  i  u  ɔː  əː  iː uː
P a  ʌ  ɪ  ʊ  aː  ʌː  ɪː ʊː
—————————————- ɔ > ɔə, i u > ɪ ʊ, ɪː ʊː > ei ou
B ɔə ə  ɪ  ʊ  ɔː  əː  iː uː
P a  ʌ  ɪ  ʊ  aː  ʌː  ei ou
—————————————- ei > ai, ɪ > ɛ, ə əː > ɪ ɪː, ɔə > uə
B uə ɪ  ɛ  ʊ  ɔː  ɪː  iː uː
P a  ʌ  ɛ  ʊ  aː  ʌː  ai ou
—————————————- a aː > ɒ ɒː, ɛ ai > æ æː, ɪː > eː, ou > oː
B uə ɪ  æ  ʊ  ɔː  eː  iː uː
P ɒ  ʌ  æ  ʊ  ɒː  ʌː  æː oː
—————————————- æ > æ or iə (conditions todo), iə uə > iː uː, æ æː > a aː, eː oː > ei ou, ɔ ɔː > o oː, ɒ ɒː > ɔ ɔː, ʌ ʌː > ɛ ɛː, ʊ > ə, ou > əu
  uː ɪ  a  ə  oː  ei  iː uː
  ɔ  ɛ  a  ə  ɔː  ɛː  aː əu

- Unstressed /i/ didn't completely lower, so it gives /ɛ/ when it isn't lost. Unstressed /ə u/ merge, although /u/ is sometimes lost. Unstressed /a/ > /o/.
- Unstressed /a ə i u/ sometimes tensed word-finally when an even number of syllables from the stress peak.
- Long vowels and diphthongs generally become vowel + approximant sequences: oː ei iː uː > ob eg ig ib, ɔː ɛː əu > ab ag eb.
- There are two types of vowel shortening: those inherited from before the vowel shift and those that developed after it. So:

aː ɛː ɔː ei ou iː uː
a  ɛ  ɔ  ɪ  ə  a  ə
a  a  a  e  ə  i  i~u