عنوان مقاله [English]
The third person singular enclitic verb /-ast/ which is equivalent to English verb “is” undergoes the highest number of phonological processes among Persian enclitic forms of the verb “boudan” (to be); It changes to [as] in one environment, to [s] in another, and to [e] in four environments. Deletion of /t/ is common in all six contexts. These different pronunciations are determined by various phonological processes including resyllabification, deletion of a vowel or insertion of an intervocalic consonant in order to resolve hiatus, vowel- consonant harmony, apocope, epenthesis, and raising. The primary cause of most of these phonological processes is the fact that this enclitic starts with a vowel. Consonant deletion is another cause. The ultimate goal of this research is to come up with a single inclusive ranking of constraints which explains all the three pronunciations of enclitic verb “-ast” in different contexts within Optimality Theory (Prince and Smolensky, 1993/2004). The results section of this research includes six facts about the phonology of this enclitic verb.