Prosodic well-formedness and sonority constraints: epenthesis in Irish

1. Introduction Early accounts of epenthesis in Optimality Theory focused on epenthesis that results from constraints on prosodic structure, that is, from syllable structure constraints or minimal prosodic category (e.g. minimal word) requirements. McCarthy & Prince (1993a) account for word-internal consonant epenthesis at V-V junctures in Axininca Campa, for example, by ranking ONSET (Syllables must have onsets) higher than the faithfulness constraint FILL (Syllable positions are filled with segmental material). Thus the input /i-N-koma-i/ he will paddle yields the optimal epenthesised output form iAkoma6i: (1) Input = /i-N-koma-i/ Candidates ONSET FILL Similarly, a constraint on the minimal prosodic structure of words in Axininca Campa, FTBIN (Feet must be binary under syllabic or moraic analysis) results in augmentation by epenthesis of monomoraic roots to bimoraicity. Epenthesis can also be expected to result from other classes of constraints, or from the interaction of other constraints. This paper focuses on epenthesis patterns in Irish which are shown to be the result of interaction between a sonority-driven intrinsic ranking of consonant clusters and constraints on prosodic structure, specifically on foot structure. An initial set of data is presented in §2.1 and an account that refers to a universal ranking of consonant clusters in terms of 'minimal sonority distance' is proposed in §2.2. Additional data are presented in §2.3 which are prosodically more complex and which require an account that involves constraints on prosodic structure. It is shown that although the cluster constraints compel epenthesis, the higher ranking prosodic constraints are shown to constrain it. Of additional interest in the proposed account is the non-ranking of two prosodic constraints, vis. NONFINALITY and PARSE-SYLLABLE. It is shown that these constraints must crucially be unranked in Irish in order to allow the contrasting effects of different cluster constraints to emerge.