In this paper I have tried to show how the Middle Persian past tense changed to what it is in New Persian. The Middle Persian past tense is constructed ergatively in terms of verb agreement, while the present tense is constructed accusatively. By constrast, New Persian has the accusative construction in both tenses. Thus, the change from Middle Persian to New Persian is a process called “accusativization”. I have tried to explain the mechanism of this process with reference to the notion of subject in ergative and accusative languages.
