The Semantic Roles of the Preposition?? az? in Persian Language

Language, like a living being, changes through time and studying of its characteristics in its present form without considering diachronic changes is incomplete and insufficient. In this article, the semantic roles of the preposition “’az” in Avestan, Old Persian, Middle Persian, Parthian, Dari Persian and New Persian languages have been studied by using grammatical data in these languages and their glossaries. In Avestan and Old Persian “’az” has appeared in the form of hača/hačā and is derived from the root “hak-”, i.e., “to accompany?”. In Middle Persian and Parthian, it has remained as “az” and “až” respectively. In Vedic Sanskrit, this preposition has been used in the form of “sačā ” to refer to the semantic role of accompaniment. But, in ancient Persian languages, there is no evidence of encoding the semantic role of accompaniment with “hača/hačā”. In Avestan and Old Persian languages, “hača/hačā” has implied different semantic roles like source, separation, cause, method. Also, in Middle Persian and Parthian languages, the functions of “az” and “až” have been preserved while some other semantic roles like instrument, nature, comparison, and part-whole relationship have been encoded. In addition to its functions in previous periods, in Dari and New Persian, “az” has the role of encoding other semantic roles, and in the encoding of some semantic roles like instrument and nature, it could be substituted with the preposition “bâ”