A Default Inheritance Hierarchy for Computing Hebrew Verb Morphology ............................................................................................................................................................ Raphael Finkel and Gregory Stump University of Kentucky, USA ....................................................................................................................................... Abstract We apply default inheritance hierarchies to generating the morphology of Hebrew verbs. This approach represents inflectional exponents as markings associated with the application of rules by which complex word forms are deduced from simpler roots or stems. The high degree of similarity among verbs of different conjugation classes allows us to formulate general rules; these general rules are, however, sometimes overridden by conjugation-specific rules. Similarly, a verb’s form within a particular conjugation is determined both by default rules and by overriding rules specific to lexical stem peculiarities. Our result is a concise set of rules defining the morphology of Hebrew verbs in all conjugations. We express these rules in KATR, both a formalism for default inheritance hierarchies and associated software for generating the forms specified by those rules. As we describe the rules, we point out general strategies for expressing morphology in KATR. We conclude by discussing KATR’s advantages over ordinary DATR for the representation of morphological systems and our plans for KATR’s successor, LATR. ................................................................................................................................................................................. 1 Introduction Recent research into the nature of morphology suggests that the definitions of a natural language’s inflectional system must be both inferential and realizational (Stump, 2001). A definition is inferential if it represents inflectional exponents as markings associated with the application of rules by which complex word forms are deduced from simpler roots and stems; an inferential definition of this sort contrasts with a lexical definition, according to which an inflectional exponent’s association with a particular set of morphosyntactic properties is listed in the lexicon, in exactly the way that the association between a lexeme’s formal and contentive properties is stipulated. A definition of a language’s inflectional system is realizational if it deduces a word’s inflectional exponents from its grammatical properties; a realizational definition contrasts with an incremental definition, according to which words acquire morphosyntactic properties only by acquiring the morphology which expresses those properties. The conclusion that inflectional systems should be defined realizationally rather than incrementally is favored by a range of evidence, such as the widespread incidence of extended exponence in inflectional morphology and the fact that a word’s inflectional exponents often underdetermine its morphosyntactic content (Stump, 2001). Moreover, inferential–realizational definitions can avoid certain theoretically unmotivated distinctions upon which lexical or incremental definitions often depend. For instance, inferential–realizational definitions do not entail that concatenative and nonconcatenative morphology are fundamentally Correspondence: Raphael Finkel E-mail: raphael@cs.uky.edu Literary and Linguistic Computing, Vol. 22, No. 2, 2007. ß The Author 2007. Published by Oxford University Press on behalf of ALLC and ACH. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org 117 doi:10.1093/llc/fqm004 Downloaded from https://academic.oup.com/dsh/article/22/2/117/940075 by guest on 10 October 2021