An investigation of Delvari preposition " si": A relic from an Old Persian preposition or the outcome of grammaticalization?

This paper aims at describing the syntax-semantics of a frequent preposition [si] in Delvari and investigating its origin based on the extant evidence. The study shows that [si], as a non-predicative preposition, only hosts an object clitic, while it takes an NP complement, bearing as diverse thematic roles as goal, recipient, benefactive, patinet and purpose in its predicative usage. As to its historical origin, one hypothesis asserts that [si] is the result of phonetic change from an Old Persian preposition [aɵiy], followed by an extension in its meanings and usages. The existence of a phonetically similar preposition with a limited usage in the same meaning as [aɵiy] and the irriversibility of grammaticalization render this hypothesis less tenable. According to the second hypothesis, [si] is the grammaticalized form of the noun [sōg/suy]. Diachronic evidence from the evolution of Persian and the data from regional dialects make the second hypothesis more likely.