Diachronic study of information structure in Persian

The present study aimed to investigate diachronic changes in the frequency and function of marked syntactic structures, namely passive constructions, preposing, and cleft sentences that manifest information structural elements in Persian. The study examined these structures across three periods of Persian, i.e., Middle Persian, Dari, and Modern Persian. The data for Middle Persian is sourced from The Mēnōg-ī Khrad and Oshnar-I Dana, while for Dari, Tārīkh-i Bayhaqī and Safarnāma by Nasir Khusraw are used. For Modern Persian, written resources from various genres, such as short stories and scientific articles, are analyzed. The samples from each period are analyzed to determine the function and frequency of marked syntactic structures, which are then compared to identify any potential changes in their usage over time. The findings indicated that the frequency and function of these syntactic structures have changed over time. The findings suggested that passive constructions were commonly used across all three periods to present the patient as the pragmatic topic and maintain the topic-focus order. However, in modern Persian, passive construction was also used to emphasize the patient as the focus. Cleft constructions were not found in Middle Persian, but the increase in frequency of cleft constructions in Dari can be attributed to the fact that in this period, cleft sentences were used similarly to preposing, in order to observe the principle of separation of role and reference, rather than focusing on specific elements. Nonetheless, in modern Persian, cleft constructions were used to exclude other possibilities and emphasize the selected element as the focus. Preposing structures were used to present an element as the topic and provide new information about it. This study contributes to our understanding of language change and provides insights into the evolution of Persian syntax over time.