|Abstract:||In Majorcan Catalan, the process of vowel reduction of the mid front vowels to schwa in unstressed position underapplies under certain circumstances: a) in productive derived forms with an unstressed vowel located in the left syllable of the stem which alternates with a front mid vowel in the stem of the primitive; b) in verbal forms with an unstressed vowel located in the left syllable of the stem which alternates with a front mid high in another verbal form of the same inflectional paradigm; c) in learned and loan words with an unstressed 'e' located in the left syllable of the stem and preceded by a labial consonant. According to my view, there are two main factors which conspire to bring about this situation: a) as detected in previous studies, the inclination of these vowels to become similar to the corresponding vowels which appear in the same inflectional or derivational paradigm, especially when the derivative process is productive; b) the privileged status of the vowels located in the left syllable of the stem. In order to account for the first factor, I propose a novel explanation framed within the Transderivational Correspondence Theory (TCT) (Benua 1997 / 2000) and the Optimal Paradigms model (OP) (McCarthy 2005). In order to account for the second factor, which has passed unnoticed in previous examinations of the same data, I assume the Positional Faithfulness Theory (Beckman 1998 / 1999). In this paper I show how the analysis of these data leads to some interesting theoretical implications. First is the need to relativize the TCT according to the type of derivation, along the lines of Ohannesian & Pons (2009). Second is the corroboration this analysis provides that the left syllable of the stem is indeed a prominent structural position that entails finer faithfulness requirements than other structural positions, as well as the occurrence of segments with high sonority. Two collateral implications of the analysis of these data are the following. On the one hand, the confirmation that the surface schwa that appears before s+C word-initial clusters in this dialect is undeniably an epenthetic vowel which does not belong to the stem, and this has obvious consequences for the different approaches to the determination of underlying representations. On the other hand, the observation that Majorcan Catalan productive phonology (including loans and learned words, and also structures derived by paradigmatic pressure) clearly favors the front mid high vowel instead of the schwa in unstressed position.