PIE inheritance and word-formational innovation in Slavic motion verbs in -i-

The unprefixed imperfective verbs of motion with present tense in -i (such as Russian vodit’, vozit’, bežat’), most of which are considered indeterminate in the modern languages, developed over a lengthy period from Proto-Indo-European to the disintegration of Proto-Slavic. The final period of their development in Slavic shows striking innovation in the formal and semantic structures, including quasi-serialization in the compounding of verbal stems in such a way that the main lexical verb is modified by a manner component, e.g., *ja‘travel’ + -sd‘sit’ = jazd-i-ti ‘ride’. This innovative period in the development of motion verbs correlates with the period of migrations, which are seen as the end of the previous state of equilibrium in the Slavic speech community.