Customizing the XTAG system for efficient grammar development for Korean
Juntae Yoon, Chung–hye Han, Nari Kim, Meesook Kim · 2000
This paper addresses linguistic and implementation problems for a practical LTAG parser raised by rich morphology in Korean. We propose a way of representing the Korean inflectional system as feature structures in lexicalized elementary trees, and describe our implemented mod-ifications on the XTAG system for a more efficient grammar development for Korean. 1. Issues Korean is an agglutinative language with a very productive inflectional system. Inflections include postpositions on nouns; tense morphemes and endings that indicate sentence types on verbs and adjectives; among others. Furthermore, these inflections can combine with each other to form compound inflections. (1) Noun a. hakkyo-ka school-Nom b. hakkyo-eyse-ka school-from-Nom c. hakkyo-eyse-man school-from-only d. hakkyo-eyse-man-un school-from-only-Topic (2) Verb a. ka-ss-ta go-Past-Decl b. ka-si-ess–ta go-Honor-Past-Decl c. ka-ki-ka go-Nominalizer-Nom d. ka-si-ess-ki-ey-nun go-Honor-Past-Nominalizer-to-Topic This implies that a word in Korean can have a very large number of morphological variants. For example, verbs can be followed by honorific and tense morphemes which can then be followed by endings indicating clause-type which then can be followed by case postpositions. Similarly, adverbial postpositions which correspond to English prepositions, can be followed by other case postpositions such as nominative or accusative case markers and auxiliary postpositions such as to (‘also’) and man (‘only’), which then can be followed by a topic marker. Accordingly,