Type grammar meets Japanese particles

Type grammar meets Japanese particles Kumi Cardinal Keio University, Japan cardinal@sfc.keio.ac.jp Abstract. This paper presents a computational analysis within the framework of a type grammar for the treatment of Japanese particles. In Japanese, particles express a number of functional relations; they follow a word to indicate its relationship to other words in a sentence, and/or give that word a particular meaning. We explain our parsing technique and discuss about various constructions using case particles and focus particles. We show how troublesome phenomena such as scrambling and omission of case particles are treated. 1 Introduction As the need of software modules performing natural language processing tasks is growing, in depth grammatical analyses of sentences must be properly carried out. Grammatical analyses based on theoretically sound grammar formalisms are thus essential. Treatment of case particles constitute an essential part of a grammar for the Japanese lan- guage, where the word order is relatively flexible. The role of case particles is functionally deter- mined within a sentence: they indicate that the accompanying noun functions as subject, object, etc. But because case components are often scrambled or omitted and because case particles dis- appear when case components are accompanied by the topic marker wa or other special particles, it makes it difficult to syntactically analyze Japanese sentences. Various studies in the literature discuss about the Japanese argument case marking and the treatment of Japanese focus particles. Here, we explore the treatment of Japanese particles within the Lambek style pregroup grammar. The application of pregroups in natural language processing provides a rigorous formulation of the grammar of a given language. Pregroup calculations are very simple from a computational point of view. Furthermore, in analyzing a sentence, we go from left to right and imitate the way a human hearer might proceed: recognizing the type of each word as it is received and rapidly calculating the type of the string of words up to that point. The reader might be curious to see a comparison of our grammar formalism with other existing formalisms such as HPSG. Indeed, it would be interesting to write our proof-theoretic analysis in terms of the model-theoretic HPSG framework. We could perhaps follow the HPSG analysis of Japanese presented by Siegel in [13], where particles are analyzed as heads of their phrases and the relation between case particle and nominal phrase is a head-complement relation. To account for the omission and scrambling of verbal arguments, Siegel introduces the attributes SAT, which denotes whether a verbal argument is already saturated, optional or adjacent, and VAL, which contains the agreement information for the verbal argument. Siegel also presents a Japanese head-complement schema which accounts for optional and scrambable arguments as well as for obligatory and adjacent arguments. Due to limited space, however, page-filling representations in the HPSG framework will not be further discussed. 142 2 Kumi Cardinal 2 The calculus of Pregroup The concept of pregroup has been developed as an algebraic tool to recognize grammatically well-formed sentences in natural languages [8–11]. Pregroups are …

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