Task: Question Generation
Input (English): Catalan has inherited the typical vowel system of Vulgar Latin, with seven stressed phonemes: /a ɛ e i ɔ o u/, a common feature in Western Romance, except Spanish. Balearic has also instances of stressed /ə/. Dialects differ in the different degrees of vowel reduction, and the incidence of the pair /ɛ e/.
Output (English): What is the exception to this common characteristic?