This study is based on the conviction that, during the final stages of the evolution of Common Slavic, shortly before the well-known split into its major dialectal areas, there occurred a series of rapid and far reaching morphological changes, parallel to and similar in scale to the far-reaching phonological changes that have become a commonplace in the scholarship, especially in the nominal system. Oddly enough, despite the vast literature on the topic, these changes have never before been systematised. In this monograph an attempt will be made to do so. Many previous studies seem to have come to grief by leaving certain forms unexplained, and this work will attempt to plug all the gaps, as far as possible.

In broad outline the phonological framework presented by Shevelov 1964 will be followed, although differing in many points of detail.

Certain automatic assumptions have been made about the declensional systems and early phonological processes in Late Indo-European and early Common Slavic which have often caused scholars to take slightly erroneous reconstructions as their starting point.

In the body of the monograph there will be repeated recourse to typological arguments, and therefore at this stage a brief discussion of typology is in order. I share most of the caveats expressed by Schmalstieg 1980: 17Ð18, with regard to typological arguments, but I would like to modify them somewhat, and suggest that typology in linguistic reconstruction, like politics, should be regarded as "the art of the possible, rather than the probable", or, in other words, if a reconstructed development can be DEMONSTRATED to have ACTUALLY occurred AT LEAST ONCE, the respective development is thereby rendered more likely (cf. especially the discussion of Indo-European ergativity and gender, and related proposals regarding case-marking). Furthermore, typological parallels rarely provide exact matches; e.g., the SEQUENCE of stages which I reconstruct for the development of Indo-European gender may well be unique, although each individual stage can be shown to be have typological parallels.

It should be emphasised, however, that the solutions to be advanced in these pages are not being offered as definitive, but rather as possible alternaÂtives. It is possible that other scholars might take individual points from this proposal, modifying them to produce a fresh synthesis.

Certain assumptions are being made for the purposes of this monograph. They will be listed in point form here, although they will be fully discussed in the body of the text, often being repeated at different points from different angles, and extensively cross-referenced.

1) Resorting to special sound changes peculiar to the final syllable of a word (Auslautgesetze; ALG) is unnecessary in the reconstruction of Common Slavic, despite the long tradition of doing so. Explanations based on morphological solutions are therefore to be preferred to explanations which postulate typologically unlikely sound-changes which only take place in isolated forms. Specifically, Common Slavic final *-om and *-ons would not have developed into *-u and *-y, but would have merged in *-o.

2) Within the Indo-European languages of Europe Slavic has shown the strongest tendency to preserve most of the inherited compliÂcated nominal morphology; number, gender, and case, while unÂdergoing massive phonological and phonetic changes. This is in contrast to most of Germanic (which underwent similar changes and lost most of its case and gender distinctions, cf. the evolution of English, Dutch, Continental Scandinavian, and, to a lesser extent, German, but cf. Insular Scandinavian), and even Baltic (which has maintained and even extended the case system, while generally reducing the gender system). Indo-European passed through a stage of ergativity, and its ergative constructions left traces in Common Slavic, which may be glimpsed in the nominal morphology.

3) Finally, as a general rule, Slavic may well have been more archaic morphologically than Baltic, even Lithuanian, although less so phonologically. This should be borne in mind when comparisons using Baltic data are made.

4) The *u-stem declension was even more numerous in Common Slavic than is commonly supposed, with possibly nearly three hundred members, and exercised a much greater influence on both the *o-stems and *‚-stems than is at first apparent from the material (see Orr 1996).