Grammaticalization and inflectionalization in Iranian

The oldest attested Iranian languages underwent erosion and loss (or at least simplification) of much of their inherited inflectional morphology. These processes, echoing similar developments elsewhere in Indo-European, affected the categories of gender, case, aspect, person, and modality. The modern languages have since restored the old categories to varying degrees, providing a rich source for observing the mechanisms of grammaticalization. This chapter focuses on the innovation of inflectional person marking, based on erstwhile clitic pronouns. While person indexing for subjects may adhere to the predicted pathway for the grammaticalization of agreement, yielding obligatory verb-bound agreement markers in some languages, the grammaticalization of object indexing does not progress beyond the stage of clitic pronouns, despite the same etymological origin as the subject pronouns, and an even longer time-depth. The chapter also discusses the grammaticalization of a new accusative case marker in Persian, and of an innovated progressive aspect.