Rule Inversion in Persian: The Optional Change of /e/ to [a] in The Standard and Esfahani Accents

In the earlier verities of Persian language including the Standard and Esfahani accents the vowel /a/ used to occur word-finally which changed to /e/ through time. Moreover, the synchronic occurrence of this process in other word positions is productive in the Esfahani accent which is regarded its well-known feature. However, presently the vowel /e/ optionally changes to [a] in the environment before the postposition “ra’’ in both accents, as well as in other environments in the pronunciation of middle- aged and older Esfahani speakers. This is an instance of synchronic rule inversion the primary reason of which is hypercorrection only in Esfahani accent. This research aimed at introducing and analyzing this type of optional rule inversion within the framework of Optimality Theory (Prince & Smolensky, 1993/ 2004). The optionality which is also known as free variation is analyzed using the free ranking approach which maps a single input onto two outputs.