The absolutive form is generally used for the subjects of intransitive verbs and the direct object of transitive verbs. Special ergative forms are used for the subject of transitive verbs.
(1) used as both ergative and genitive; (2) manifests as Avar -e (dative), Hunzib -i (dative) etc., shifted to instrumental in Lak, Dargwa, genitive in Khinalug, or ergative in Tsezian, Dargwa and Khinalug
Instrumental
-z [s]
-as/-áas(1)
*-s:-(2)
(1) cf. parallel infinitive -s in some Lezghian languages; (2) instrumental animate; general attributive, shifted to closely related functions in most modern languages, e.g. ergative animate in Chechen, adjectival and participial attributive suffix in Abkhaz etc.
Genitive
-en
*-nV(1)
(1) attested as genitive in Lezghi, Chechen (also infinitive, adj. and particip. suff.), possessive in Ubykh etc.; in some languages the function has shifted to ablative (Avar), ergative (Udi, Ubykh)
Allative
-ra(1)
-r/-ar(2), -al-(3)
*-ɫV(4)
(1) some northern Basque dialects have the form -rat and/or -lat; (2) dative/allative; (3) locative; (4) Chechen -l, -lla (translative), Tsez -r (dative, lative), Khinalug -li (general locative) etc.
Comitative
-ekin
*KV(1)
(1) possible cognates among mutually incompatible suffixes, cf. Avar -gu-n, -gi-n (comitative), Andi -lo-gu, Karata -qi-l, Tindi -ka, Akhwakh -qe-na.
The stressed penultimate syllables in PDC give rise to the morpheme-wide tenseness in PNC. As only fricatives and affricates can be tense in PNC, their absence makes tense morphemes indistinguishable from the lax ones. The loss of the slot-3 glottal stop after long vowels in PY is another problem for the clear determination of stress in PDC.
In the following table, P represents a PNC stop consonant, whereas F a fricative or an affricate.
