Treating German with a Provably Context-Free Grammar:
Coping with Subcategorization, Unbounded Dependencies and Partial Free Word-Order

by Sascha Brawer

Proceedings of 5. Tagung der Computerlinguistik-Studenten (TaCoS), Saarbrücken, May 25 – 28, 1995, pp. 5 to 16
Available in PDF Format

Abstract

Several applications of Natural Language Processing need short processing times while retaining a certain degree of linguistic adequacy. This article describes some techniques employed in a text-to-speech synthesis system for German which allow for the parsing of sentences containing linguistic phenomena such as unbounded dependencies, subcategorization and free word order in the German Mittelfeld. The grammar is restricted to the unification of atomic terms only. It is shown that every grammar using such a formalism is equivalent to a context-free grammar.

Although the article may be of some theoretical interest — there is fairly widespread agreement in Computational Linguistics that complex linguistic phenomena cannot be handled with context-free grammars —, some of the presented techniques could be useful for implementing fast language processing without too much loss of linguistic adequacy.

It has to be mentioned explicitly that the article does not state any linguistic theory, it simply describes a method for coping with certain phenomena in way which enables fast processing.