In recent functional and cognitive literature different motivations are suggested to influence the relative clause extraposition, where the modifying relative clause is not adjacent to the modified head noun. Information status, grammatical weight and verb class are among such motivations. The current corpus based study of relative clause extraposition attempts to test the prediction of these different motivations in Persian. Using logistic regression analysis, the effects of these various factors on the extraposition of relative clauses are investigated. The findings revealed that, among different influential sources, grammatical matical weight is the main factor influencing extraposition of relative clauses. Verb class and information status are found to be lower ranked factors, respectively.
