This paper provides an analysis of Persian verbs within the framework of Optimality theory. To be more specific, it mainly cocentrates on past and present stems of Persian verbs.
Since analyzing this subject within the derivational framework would result phonological rules which are not natural, it is analysed by Optimality theory which is one of the constraint-based approach.
Based on this, we hypothesized that past stem is derived from present stem by adding past morpheme. Later , using violation and comparative tableau, we argued that past stems of the Persian irregular verbs are dominated by two violable markedness constraints.