Old Veyata - Evolution into Veyrathi and Veytharian

Basic idea

Old Veyata is the last common major stage before the later Eastern and Western standards clearly separate. The two daughter languages do not emerge directly from Proto-Veyata, but from late Old-Veyata dialect chains that generalize various tendencies:

Veyrathi smoothes, shortens function words and pulls the sentence into transparent SVO.
Veytharian condensed, builds up stronger verb brackets and preserves more old edges or replaces lost categories with new auxiliary constructions.

Regular sound and form correspondences

Old Veyata	Veyrathi	Veythar	Typical effect
`ara`	`ar`	`ae`	definite article splits into short east and narrow west form
`ora`	`or`	`our`	Distal shape is reduced in two directions
`ey`	`ey`	`ei`	Erbdiphthong stays east, moves west
Verb on `-a`	Basic form on `-a`	Infinitive on `-en`, finite stem	Westen builds a new lexicon/inflection pattern
Past `-na`	`-n`	mostly `-ed/-t`	East cuts, West remodels
`-atha`	`-ath`	`-eth`	Abstract suffix differentiates in both directions
animated plural `-iri`	`-ir`	`-ei`	old social plural remains recognizable, but phonetically different
collective plural `-na`	`-n`	`-en`	Eastern smoothing vs. Western closed ending
`=ren`	`'ren`	Function mostly captured via `na`	Ownership is clearly drifting apart
`ka`	`ka`	`ha`	Question particle is further reduced in the West

Grammatical drift

Old Veyata	Veyrathi	Veythar
mixed `SOV/SVO`	`SVO` becomes standard	`V2` in the main clause, verb later subordinate clauses
present often copulaless	present and often copulaless	Copula `is` becomes standard
`sai` + verb	`sa` + verb	`lai` + infinitive
`hana` + past tense	`han` + past tense	`hei` + participle
Verb + `ra`	merges into `-ra`	Future again with Auxiliar `sha`
Oblique `-i`	largely lost	Functions distributed across oblique pronouns and adpositions

Cognate paths

Meaning	Old Veyata	Veyrathi	Veythar
speak	`veyra`	`veyra`	`veiren`
see	`seyra`	`seyra`	`seiren`
go	`tala`	`tala`	`talen`
give	`nava`	`nava`	`naven`
speech	`veyratha`	`veyrath`	`veireth`
Advice	`thalor`	`thalor`	`thal`
contract	`kevara`	`kevar`	`kevar`
strong	`draz`	`draz`	`draes`
new	`zeya`	`zeya`	`zei`
definitely/near	`ara`	`ar`	`ae`

Pronominal development

Alt-Veyata keeps short and full forms side by side.
Veyrathi standardizes the shorter forms as an everyday system and uses them to build clearer standard paradigms.
Veytharian, on the other hand, increases the distance between direct, oblique and possessive forms:
nu -> nai / naim / nain
se -> sae / saem / saen
The neutral form se remains recognizable in both lines, but its morphology drifts strongly.

Structural effect

Seen from Alt-Veyata, Veyrathi seems like the smoother, more open and clearly segmented sequel.
Veytharisch seems like the denser, more regional and morphologically new continuation.
So both resolve the same Alt-Veyata tensions differently:
East: reduction and standardization
West: consolidation and reorganization

Overall conclusion

Old Veyata is the place where the late family still remains legible as a common system. Only from here do the later differences become truly systematic:- SOV/SVO becomes SVO or V2

ra is replaced to suffix or back to auxiliary field
=ren becomes possessive marker or gives way to a na strategy
open solid forms become smooth eastern forms or dense western forms