It is well known that during the course of their histories a number of Indo-European languages, all of them members of the Indo-Iranian branch of the family, developed an ergative construction. Thus, in certain tenses of the verb, their grammars came to treat in formally identical manner the subject of an intransitive verb and the logical object of a transitive verb, the agent (or logical subject) of this latter being given a different morphological marker. Now although ergativity has been studied in a wide variety of languages as a synchronic phenomenon, the opportunities for examining it from a diachronic point of view are in the great majority of cases severely limited by lack of historical documentation. The Indo-Iranian languages, however, form a notable exception. These, thanks to the availability of texts from closely related languages covering a time-span of some three millennia, provide us with a chance to observe both the development of the construction and its subsequent decline. The present paper will do no more than attempt to trace a part of this process, namely the way in which the ergative construction has disappeared from a certain area of western Iranian. It bases its arguments upon the assumption that the geographical continuum of the Kurdish dialects, whose grammars exhibit the whole range of possibilities from fully ergative systems in the north to fully accusative systems in the south, reflects the successive stages of a diachronic process. This being granted, it should be possible by ordering the synchronic patterns of representative dialects from the northern, the central and the southern regions, to arrive at a picture of the historical sequence of events which has led to the loss of ergativity in the southern dialects and to isolate the mechanisms involved in their resultant restructuring. The wider problems of precisely how the construction arose historically and of why within the Indo-European family it appears to be confined to Indo-Iranian will not be dealt with here.
The dialects of central Kurdistan can be divided at approximately the latitude of Mosul into a northern and a southern group, the line separating them following roughly the course of the Greater Zab, an eastern tributary of the river Tigris in Iraq. The northern group will be represented in our discussion by the dialects of Amadiye and Sinjar (Blau, 1975) and by a somewhat normalized variety of Kurmanji (Bedir Khan and Lescot, 1970), the southern dialects by Mukri (Mann, 1906-9) and Suleimaniye (MacKenzie, 1961). For the Suleimaniye sentences I am indebted to a native speaker of that dialect, Mr. W. O. Amin, who is at present working on a grammatical description of his language. In addition to the above, I have relied heavily for all the Iraqi dialects on the wealth of information contained in MacKenzie (1961). The transcriptions are in all cases those of my sources.
We shall first examine the relevant syntactic patterns in the northern dialects. In these both the noun and the pronoun inflect for case. Apart from the vocative (which does not concern us here), there are two cases, the direct and the oblique, formally distinguished either by means of suffixes or, in the case of certain pronouns, by suppletive forms. Ergativity, as is also the case in those other Indo-Iranian languages which exhibit it, is confined to the so-called past tenses of the transitive verb. The past tenses comprise paradigms employing both simple and periphrastic constructions. The latter, which are formed by means of a participial form of the main verb and an auxiliary, will not be dealt with since they are irrelevant to the problems under discussion. The simple past tenses are derived by means of aspectual and modal prefixes from the past stem of the verb. The present tenses are derived in parallel fashion from the present stem, although they do not have an ergative construction. A simple verb form, whether present or past, consists of three elements: a prefix, a verb stem and a suffixed person-number marker (or ‘ ending ‘). The sets of person-number markers employed in the present and past tense paradigms differ formally only in the third person singular, the present tenses here having an overt marker, the past tenses zero. Thus, in Kurmanji: