Patterned Exceptions in Phonology

Kie Ross Zuraw
University of California, Los Angeles, 2000
Professor Bruce Hayes, Co-chair
Professor Donca Steriade, Co-chair

Standard Optimality-Theoretic grammars contain only the information necessaryto transform inputs into outputs; regularities among inputs are not accounted for. Using the example of Tagalog nasal substitution, this dissertation presents a model of how lexical regularities could be learned, represented in the grammar, used by speakers and listeners, and perpetuated over time.

Lexical regularities are represented as low-ranking constraints, their rankings learned through exposure to the lexicon using Boersma’s Gradual Learning Algorithm. High-ranked constraints ensure the primacy of listed pronunciations; but when a speaker produces a novel word, these high-ranking constraints are irrelevant and the constraints that encode lexical regularities take over. The subterranean constraints are stochastically ranked; speakers’ behavior on novel words probabilistically reflect the lexical regularities. The listener uses the same grammar to produce well-formedness judgments for novel words and to reconstruct inputs from an interlocutors’ outputs. The model’s well-formedness judgments reproduce the experimental result that although the productivity of nasal substitution on novel words is low, nasal-substituted novel words are judged more acceptable than non-substituted words in certain cases.

Bayesian reasoning by the listener favors novel nasal-substituted words—they are disproportionately likely to become listed. A computer simulation of the speech community confirms that although nasal substitution is the minority pronunciation for novel words, a word may eventually enter the lexicon as nasal-substituted.

Tagalog vowel raising under suffixation is close to exceptionless in the native vocabulary but quite exceptionful among loanwords. A loan stem’s probability of resisting raising is highly influenced by its degree of internal similarity. I propose that internal similarity encourages speakers to construe a word as reduplicated, even without morphosyntactic motivation; raising is blocked because it would disrupt base-reduplicant identity.

Alternatives to encoding lexical regularities in the grammar are considered. It is argued that the vowel raising facts are not amenable to an associative memory account. The qualitative difference between “regulars” and “exceptions” cited by proponents of the Dual-Mechanism model as evidence for leaving lexical regularities out of the grammar reduces to a difference between listed words and synthesized words; this difference can arise through listener reasoning, without a prior qualitative difference.

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