Analyzing Embedded Noun Phrase Structures Derived from Japanese Double-Nominal-Case Construction

Embedded noun phrase structures are frequently used in the Japanese language because embedded sentences make modified noun phrases more expressive. In embedded noun phrase structures, a noun phrase modified by an embedded sentence is usually created by extraposing the case, such as the subjective case, of the sentence. In contrast, there is another type of embedded noun phrase structure. In this type, the noun phrase modifying a certain case of the embedded sentence is extraposed. As conventional methods for analyzing embedded noun phrase structures do not take the existence of the Japanese double-nominal-case construction into consideration, the latter type of embedded noun phrase is handled as an exception. This paper describes a method for analyzing the latter type of embedded noun phrase structure based on the valency structure in the Japanese-to-English translation system called ALT-J/E. We regard the latter type as the structure derived from the Japanese double-nominal-case construction in which the adverbial particle "wa" is a proxy for the pre nominal particle "no". This point of view leads us to analyze both the former and the latter types of embedded noun phrase structures uniformly based on the valency structure of embedded sentences. Moreover, this paper describes an evaluation that clarifies the validity of the proposed method. The evaluation results show that about 86 % of the latter type of the embedded noun phrase structures are correctly analyzed by the method proposed here. This means the proposed method is valid for analyzing embedded noun phrase structures derived from Japanese double-nominal-case construction.