The origin of this construction is usually placed in a shift in the meanings of certain verbal forms between
Proto-Semitic and the
Central Semitic languages. In Proto-Semitic, still largely reflected in
East Semitic, prefix conjugations are used both for the past and the non-past, with different vocalizations. Cf.
Akkadian niprus "we decided" (preterite),
niptaras "we have decided" (perfect),
niparras "we decide" (non-past), vs. suffix-conjugated
parsānu "we are/were/will be deciding" (stative). According to Hetzron, Proto-Semitic had an additional form, the
jussive, which was distinguished from the preterite only by the position of stress: the jussive had final stress while the preterite had non-final (retracted) stress. Central Semitic significantly reshaped the system: Essentially, the old prefix-conjugated jussive broadened to cover the non-past in general, while the stative switched from a non-tense-specific form to something specifically indicating a past action; meanwhile, the old prefix-conjugated non-past was discarded, as was the prefix-conjugated past (which increasingly came to sound the same as the prefix-conjugated jussive). New suffixes were added to distinguish different
grammatical moods (e.g.
indicative mood vs.
subjunctive vs. jussive). According to
Gotthelf Bergsträsser (1918), the emergence of the vav-consecutive took place in stages. First, the preterite */yaqtul/ and the imperfect */yaqtulu/ coalesced in Hebrew into a single verbal form, because of the loss of final short vowels. As a result, the freestanding */yaqtul/ preterite was generally lost in Hebrew. Hetzron "All attempts to explain this at first sight strange phenomenon, whereby two tenses apparently exchange functions, on logical grounds, have failed, but the historical development of the Hebrew language readily accounts for it. When it is remembered that this is a composite language containing elements drawn from all the Semitic languages, it is at once seen why it has two pronouns for the first person... So there are two different systems, drawn from different sources, merged in the Hebrew scheme of tenses." On this view, the consecutive constructions are connected with the verb systems of
East Semitic (Driver makes a comparison with
Akkadian), whereas the ordinary verb construction reflects the usage in
Northwest Semitic (
Aramaic). The two have survived side-by-side in the Hebrew verb paradigm. Vav-consecutive is attested in other
Northwest Semitic languages as well: with imperfect, in
Moabite, in
Deir Alla Inscription, and in
Aramaic; and with perfect in conditional clauses, in
Ugaritic, in
Amarna letters, and in
Phoenician. Yet, usage of vav-consecutive with perfect in a narration is unique to Hebrew. ==Obsolescence==