Fortition as one of the common phonological processes is the opposite of lenition. It occurs mostly in the initial position of the syllables and words. The present research has studied the fortition processes and evolutions from the Middle Persian to the Modern Persian based on positional strength approach. sonority sequencing principle (SSP). https://www.spidertattooz.com/WAC-4011-LED-Horizontal-Step-Light-Colorscaping/