Abstract
The main question of the study is determining the status of thematic structure in declarative clauses in the writings of advanced non- Iranian Persian learners and determining the status of markedness. This study is corpus based and done by a descriptive and analytic method. The corpus includes 49 models of writing of advanced non-Iranian Persian learners of different nationalities who have studied at Persian Language Center of Imam Khomeini International University. To do this study, at first, the thematic structure was studied in declarative clauses in the writings of Persian learners, then the kinds of themes as the point of textual, interpersonal and experiential were determined. After that, unmarked and marked themes were determined. Finally, the obtained data was presented using descriptive statistics. The findings indicated that the frequency of using experiential and multiple themes in declarative clauses was equal (each 43%). Additionally, the frequency of clause themes was 14%. Among the multiple themes, textual- experiential theme had the most frequency (88/43%). The findings also confirmed the hypothesis that the most of the themes (81%) was unmarked and the frequency of using unmarked themes in declarative clauses in the writings of advanced non-Iranian Persian learners was different in various nationalities.
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