A. Chikobava suggests that the second series of tense-aspect forms is the primary by its origin relative to the first series of tense/aspect forms, and that the opposition durative/discretive aspects is the primary relative to the opposition present/past/future tenses. The archaic imperfect must have been formed from the Iterative II by adding the -od suffix. Iterative II expressed the durative aspect, while the archaic imperfect (iterative II + the -od suffix) expressed the discretive aspect. They where not connected with the past tense and could fulfil the function of both past and present tenses. The trace of this phenomenon must be the conjugation of a verb i-c-i-s (knows) in modern Georgian: kac-ma i-c-i-s, where the subject is in the ergative case as it should be in the II series. The morphological structure of the verb is also of the II series, but this form expresses the present tense and belongs to the I series, comp. kac-ma i-c-od-a, where imperfect is formed from the form i-c-i-s by adding the suffix -od, the subject remains in the ergative case. This is an analogous way to produce a new form as in so called "mixed iterative" or "iterative formed by -od" in Old Georgian. The author of this hypothesis finds confirmation to this assumption in Old Georgian translated sources where the verbs represented in the present tense in Greek and other languages are translated into Georgian with the forms of the Iterative II (which usually expresses the past tense nowadays)  (A. Chikobava, Ergat'iuli k'onst'rukciisatvis iberiul-k'avk'asiur enebshi [Ergative Construction in Ibero-Caucasian languages], Tbilisi, I, 1948).