Abstract-This paper sheds new light on Persian Linguistics; meanwhile to criticize the traditional trends pushed theoretical linguistics formal approach) and applied linguistics (Functional approach 1 ) part; as well as welcome the evidence and opportunities that this mixed approach provide for bringing them together. This model of analysis will be known as a mixed model that can achieve more comprehensive responses for Persian diversities than considering each approach in isolation. They're both are vital for Persian syntactic analyses; they are complementary. Relying on each approach is misleading. The main objective is to support this claim by evidence from Persian Language. The Persian evidence shows the constraints and varieties in this language is not only originated from syntactic principles, but also they are greatly motivated by pragmatic considerations. Therefore the variety of syntactic structures such as wh-constructions, sluicing, ditransitive verbs and obligatory adjuncts can not be determined or stipulated by the absolute formal constraints. As an evidence the first group of constructions will be discussed.Index Terms-formal approach, functional approach, mixed approach, Persian language