Auxiliation in Persian and Evolution of Passive Structure from Stative to Dynamic Passive

Auxiliation is a subfield of the more familiar field of grammaticalization in world languages and deals with the way in which complex lexical verb structures develop over time into auxiliary grammatical structures in some of their usages. Most auxiliaries in New Persian were used just as lexical verbs in Old or Middle Persian and converted into auxiliaries through grammaticalization. The present study deals with the process of auxiliation of "shodan" in passive structure in Persian. This paper by providing instances of the passive structures in Old and Middle Persian provides an answer to the question of whether the usage of "shodan" as an auxiliary in passive structure goes back to the Old Persian or has been the outcome of grammaticalization. According to the existing evidences, the grammatical function of "shodan" in New Persian has been acquired through auxiliation during Dari (early New Persian) in the process of the evolution of passive structure from stative passive in Old and Middle Persian to dynamic passive in Dari. From typological view point, comparing the evolution of passive structure in Persian with similar processes in some other languages makes it clear that such an evolution has been due to a common tendency in languages towards dynamic passive in order to disambiguate passive structures.