Proto-Gäj language

Proto-Gäj (abbreviated PGäj; also called Proto-Gajic or Proto-Arklobu) is the reconstructed ancestor of the "Gäj" branch of the Koyanic languages.

Evolution
The earliest reconstructible stage of the Gäj branch of the Koyanic languages is Proto-Gäj. This stage of the language had already made several significant changes to the consonant inventory, including developing voiced plosives and a new set of fricatives and losing any voicedness contrast in the sonorants. Proto-Gäj reflects Proto-Koyanic laryngeals *x₁ *x₂ *x₃ by a single voiceless velar fricative *x, though it is thought the consonant was not velar and was likely voiced at the time of PKn despite the symbol *x. Proto-Gäj had also shifted some vowel qualities, resulting in the vowel inventory presented above.

The following sound changes are reconstructed to have occurred, roughly in the order presented, in the development of Proto-Gäj from its ancestor Proto-Koyanic. In each example given, the start (PKn) and end point (PGäj) for each word is shown, with relevant intermediate steps in bold.

Stem mutation
A key characteristic of Gäj morphology is stem mutation, where the underlying form of a noun or verb stem is mutated to a slightly different form in certain inflections. The two forms of the stem are known as basic and mutated.

Basic stem
The basic stem is used in the perfective verb conjugation and the absolutive, lative and oblique nominal cases. This is the unmarked form of the stem which may take any vowel and any final consonant. When vowel-initial suffixes are attached to the basic stem, *-x- is inserted between the stem and the suffix.

Mutated stem
The mutated stem is used in the imperfective verb conjugation and the ergative, genitive and ablative nominal cases.

In the mutated stem, any stem-final obstruent is regularly devoiced:


 * *b *-d *-ɟ *-g *-r > *-p *-t *-c *-k *-s

Note that while not an obstruent, *-r was mutated to *-s because the vast majority of stem-final *-r originates from PKn *-z and *-sʼ, which merged into *-z and then rhotacised to *-r after the devoicing occurred. This regular alternation between *-r and *-s was so common that it was analogically applied to forms which originally had no sibilant, such as PKn *pʰə̄́x₃r "vocal sound, speech" reflected by the PGäj stems *pʰṓr-/*pʰṓs-.

The Northern Gäj languages went on to further morphologically separate the two stem forms via ablaut in the mutated stem. For more information, see here.

The inanimate ergative suffix *-īr should have allowed voicing of the stem-final obstruent, yielding the expected forms like **ā́gīr and **érīr rather than the actual *ā́kīr and *ésīr. This indicates that these forms were changed by analogy with the pattern observed in the animate nouns, where the ergative takes the mutated stem. The semantic role of the genitive and ablative may also have influenced this analogy, since they may be considered more active or dominant roles than the absolutive, oblique and lative cases which take the basic stem.

The semantic association between the cases was strengthened in many daughter languages, in which the two stem forms of many words became separated not only grammatically, but lexically, undergoing different semantic shifts and resulting in separate words.

N-stem
The N-stem is a special modification of the basic stem found only in the irrealis verb conjugation. It is identical in form to the basic stem with the addition of a suffix which manifests as *-on on consonant-final stems and *-n on vowel-final stems, lacking the *-x- that would normally be inserted on the basic stem.

Some examples of consonant-final and vowel-final verb stems are shown below.

Transitive Verbs
Transitive verbs had three conjugation paradigms: perfective, imperfective and irrealis; which use the basic, mutated and N-stem forms respectively.

Each conjugation has a set of suffixes which mark the person of the subject and a set of prefixes and infixes which mark tense, aspect and mood information and show agreement with the plurality of the subject. The combination of suffixes and prefixes allows all six person and number combinations to be distinguished.

The imperfective suffixes appear to be descended from PKn infinitive series {*-kʰi, *-kʰīkʰ, *-ʡī} with an unknown suffix *-r and irregular infixing on the second person suffix *-kʰī⟨r⟩kʰ. This unusual development represents the only finite verb forms developed from the PKn infinitives present in the Koyanic language family.

The irrealis suffixes are the reflexes of the reconstructed suffixes of the PKn conditional series, reflecting only the singular person forms {*-(ə)ntʰx₂əʡ, *-(ə)ntx₂əʡu, *-(ə)nqtx₂ə} and dropping the plurals.

Perfective conjugation
The prefixes of the perfective conjugation are single syllables composed of two obligatory parts, an initial consonant which carries tense and person information, and a rhyme which may further specify the person.