The GF Resource Grammar Library

Abstract

The GF Resource Grammar Library is a set of natural language grammars implemented in GF (Grammatical Framework). These grammars are in a strong sense parallel: they are built upon a common abstract syntax, i.e. a common tree structure. Individual languages are obtained via compositional mappings from abstract syntax trees to feature structures specific to each language. The grammar defines, for each language, a complete set of morphological paradigms and a syntax fragment comparable to CLE (Core Language Engine). It is available as open-source software under the GNU LGPL License. The current coverage is fourteen languages: Bulgarian, Catalan, Danish, English, Finnish, French, German, Italian, Norwegian (bokmål), Polish, Romanian, Russian, Spanish, and Swedish. More languages are under construction.

The library can be used as a resource for language processing tasks, such as translation, multilingual generation, software localization, natural language interfaces, and spoken dialogue systems. The library may also have some language-typological interest as an experiment showing how much grammatical structure can be shared between languages. The focus of this paper is on the linguistic aspects of the library—in particular, what syntactic structures are covered and how the problems arising in different languages have been solved. We will also discuss the nature of the common abstract syntax with respect to translation equivalence.