Evidence Against the Context-Freeness of Natural Language

Abstract

In searching for universal constraints on the class of natural languages, linguists have investigated a number of formal properties, including that of context-freeness. Soon after Chomsky’s categorization of languages into his well-known hierarchy (Chomsky, 1963), the common conception of the context-free class of languages as a tool for describing natural languages was that it was too restrictive a class — interpreted strongly (as a way of characterizing structure sets) and even weakly (as a way of characterizing string sets).

The author would like to thank Beat Buchmann, Mark Domenig, Hans Huonker and Patrick Shann for their patience in providing the Swiss-German data, and the researchers at the Dalle Molle Institut pour les Etudes Semantiques et Cognitives for providing the impetus and opportunity to pursue this study. Special thanks go to Thomas Wasow for his extensive and continued support of this research.

The research reported in this paper has been made possible in part by a gift from the System Development Foundation, and was also supported by the National Science Foundation grant number IST-83-07893 and by the Defense Advanced Research Projects Agency under Contract N00039-80-C-0575 with the Naval Electronic Systems Command. The views and conclusions contained in this document are those of the author and should not be interpreted as representative of the official policies, either expressed or implied, of the Defense Advanced Research Projects Agency, or the United States government.