String adjunct grammars

In this paper, we have introduced a new style of formal grammars called String Adjunct Grammars (AG). The rules in an AG have a considerably different formal character as compared to the ´rewrite rule´ in a Phrase Structure Grammar (PSG). Such a study of formal grammars of different styles (i.e., formal character of rules) is of great interest because each style is well suited for characterizing certain aspects of natural language structure and is awkward for characterizing certain other aspects. Several subclasses of AG´s motivated by strong linguistic considerations have been studied, comparing them with PSG´s. Linguistic relevance of these grammars (and other gram mars suggested by this study) has been discussed at the end.