Verbs of motion
Motion verbs (VoM) are discussed as examples of exceptions to the definition of unaccusativity. The problem arises under impersonal passivization (IPass): VoM may, on the one hand, be subjected to impersonal passivization, but, on the other hand, they turn out as ergative verbs/unaccusatives in directional use. As laid out in Section 2, the clash consists in the fact that IPass is always imperfective, whereas unaccusatives are perfectives. The solution is sought in the assumption that VoM are split unaccusatives: unergatives in the present, ergatives in the preterit participle. The main body of this article is devoted to illustrating and discussing in detail this assumption. Section 3 is on split auxiliary selection and the Unaccusative Hypothesis, the search for a uniquely motivated auxiliary selection as well as transitivity and mutativity parameters. Russian verbs of motion (VoM) turn out to specify the essential distinctions of split unaccusativity (in 3.3). Event semantics and event syntax as well as event decomposition and the underspecificity of VoMs (3.3 and 3.4) further pave the pathway to an understanding of the specifics of VoM as ergatives/unaccusatives and unergatives simultaneously.Section 5 presents Scandinavian as an alternative encoding to impersonal passivization. Section 7, finally, summarizes the findings to give an answer to the question: How do agentivity and unaccusativity align? A brief discussion of Aspect-based account vs. argument-based account for passivization (Section 8) leads to the unified IPass criterion in Section 9. Section 10 furnishes the results of our discussion.