The Role of Positional Strength in The Occurrence of Assimilation Process in Persian Language Based On Sibawayhʹs View

The present study investigates the role of positional strength in the occurrence of assimilation processes in Persian language in order to determine the direction of their occurrence as regressive or progressive. The data have been collected from the corpus of "Persian Vocabulary" including about 55,000 entries and have been analyzed based on the approach of Sibawayh (2nd century AH) to the role of "positional strength" in the occurrence of assimilation processes. 33 cases of these processes in the place of articulation, the manner of articulation and the voicing features have been identified and investigated. Some of the research findings are: 1- About 94% of the types of assimilation processes in Persian language have been done regressively and only 2% have been done progressively. 2. About 58% of the assimilation processes have taken place in the manner of articulation. 3- The factor of "positional strength" has a decisive role in determining the direction of assimilation processes.