In Tātic, a modern Northwest Iranian language group, =rā is a polysemous postposition which has not evolved into an accusative marker, unlike what happened in Modern Persian. Tātic varieties, which include all Tāti, Tālyshi and Tātoid dialects spoken in northwest Iran, exploit the postposition =rā to mark many different case roles. This paper studies the various functions of the postposition =rā and its variants in this language group. The data for the study have been gathered through fieldwork and interviews with Tāti native speakers as well as through available descriptive grammars. Using the dative semantic-map approach, we show that the main functions that =rā marks in all Tātic dialects are ‘beneficiary’, ‘reason’ and ‘purpose’. We conclude that because some of the functions of =rā are not among the semantic roles in the conventional dative semantic map, this needs to be expanded in order to account for the polysemy patterns of =rā in the Tātic language group.
