An apparatus and method for an automated grammar file expansion tool are described. The method includes the receipt of a source grammar file. Once received, one or more grammar rules within the source grammar file are expanded to generate one or more expanded grammar rules. Once expanded, the one or more expanded grammar rules are provided to a grammar developer, for example, via a graphical user interface. Finally, a final grammar file is generated, including functionality of each grammar rule within the source grammar file, as well as one or more expanded grammar rules selected by the grammar developer from the expanded grammar rules.