Has anyone constructed a grammar file for English, Spanish, or other natural language?

Terence Parr

No. Naturally language is considered a much more difficult problem than the deterministic, unambiguous parsing of programming languages, data formats, and the like. That said, you can do a pretty good job of simulating an English recognizer (for an adventure game, for example) with just a few simple rules.

Natural language is just too **** hard for a deteministic parser. For example, there are multiple interpretations of Groucho Marx's: "I once shot an elephant in my pajamas."