Proto-Gäj language

Proto-Gäj (PGäj) is the reconstructed ancestor of the Nambāno and Arklobu languages, which together form the "Gäj" branch of the Arklobu-Qachkav languages.

Consonants
The voicing of the plain PAQ plosives *p *t *c *k (*kʷ) → *b *d *ɟ *g (*gʷ) is assumed to have already taken place in Proto-Gäj due to the reflection of PAQ *cʰ *c by Nambāno /s z/, which would be an unusual change without first going through the voicing step, as well as some additional evidence from Arklobu. The aspirated plosives *pʰ *tʰ *cʰ *kʰ (*kʷʰ) may well have retained their aspiration, but the only contrastive feature which can be reconstructed for Proto-Gäj is the voicedness, so their reflexes are transcribed *p *t *c *k (*kʷ).

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

Transitive Verbs
Transitive verbs had three conjugation paradigms, perfective, imperfective and irrealis, each with a different form of the verb stem.

The three forms of the stem are distinguished as follows:


 * Perfective stem — *-∅ on consonant-final roots, *-x on vowel-final roots (note realisation as *-xʷ before the 2sg, 2pl and 3pl suffixes *-ɒkʷu, *-uːp and *-uːk)
 * Imerfective stem — Mutation of final plosives *p *t *c *k *b *d *ɟ *g > *f *s *ç *x *p *t *c *k; fronting ablaut of final vowel in stem:
 * {*-i(ː)-, *-ɨ(ː)-, *-u(ː)-} > *-i(ː)-
 * {*-e(ː)-, *-ə(ː)-, *-o(ː)-} > *-e(ː)-
 * {*-æ(ː)-, *-ɒ(ː)-} > *-æ(ː)-
 * Irrealis stem — *-əN on consonant-final roots, *-N on vowel-final roots, where N assimilates to the place of articulation of the following consonant in the suffix of the irrealis conjugation (*-tæ, *-cuː *-dæu, *-ktæ).

Some examples of vowel-final and consonant-final transitive verb stems are shown below. Each conjugation has a set of suffixes which mark the person of the subject and a set of prefixes and infixes which mark TAM information and show agreement with the subject. Both sets of affixes distinguish first person singular and plural in all conjugations, while in the case of imperfective and irrealis conjugations with second or third person subjects, the person is marked by the suffix and the plurality is marked by the prefix/infix.

The suffixes are shown below. The perfective series is simply a continuation of the PAQ perfectives {*-ʡx₂əʡ, *-ʡx₂əʡx₃, *-ʡx₃əkʰʊ, *-ʡʊːpʰ, *-ʡx₃əkʰi, *-ʡʊːkʰ}, of which Proto-Gäj is in fact the primary source for reconstruction. The -(h)- is present only on vowel-final verb stems.

The imperfective suffixes appear to be descended from PAQ infinitive series {*-kʰi, *-kiː, *-kʰiːkʰ, *ʡiː} with an unknown suffix *-r and irregular infixing on the second person suffix *-ciː⟨r⟩k. This unusual development represents the only finite verb forms developed from the PAQ infinitives present in the Arklobu-Qachkav family.

The irrealis suffixes are the reflexes of the reconstructed suffixes of the PAQ conditional series, reflecting only the singular person forms and dropping the plurals. { *-(ə)ntʰx₂əʡ, *-(ə)ncʰʊːʡ, *-(ə)ntx₂əʡʊ , *-(ə)ntx₂əjʊ, *-(ə)nqtx₂ə , *-(ə)nqtx₃əʡ}. The expected form of the first person plural negative present prefix is *xæmə-, according to regular sound change from PAQ *x₂əmə, indicating that the labialised form *xʷæmə- developed through analogy with the other negative present prefixes.