Abstract :
This paper provides a diachronic optimality-based account of the principal lenition patterns witnessed in obstruents from Indo-European to New Persian through Old Persian and middle Persian. At first, a brief introduction of Optimality Theory and its basic concepts is presented. After that, the paper gives an introductory account of lenition, its definition and categorization, and then it investigates different lenition patterns that have happened in the history of Persian. Among different patterns of lenition, loss of aspiration, lenition of voiceless stops to voiced ones, spirantization, degemination, and final neutralization were witnessed in transition from IE to OP as well as from OP to NP and dealt with in this paper. For this purpose, Optimality Theory (OT) is applied to account for the changes based on major works done on lenition. Using different constraints, all of these processes are accounted for. This work indicates the success of OT in accounting for diachronic phenomena, that is, by constraint re-ranking it can adequately account for sound change.
