Jackendoff's Systems

The problem is that language is a lot more than just parsing (and there are plenty of things my parser doesn't do like learn new grammar rules).
So, how do we move forward?
I think Ray Jackendoff's book, The Foundation of Language, is a good start.
In it, he describes a tripartite theory of language, three systems, phonological, syntactic and conceptual, interact.
The systems are independent, but communicate via system to system interface rules.
There are some more systems (e.g. lexical) but that fits in with the basic systems and interfaces.
What's nice about this is it breaks the problem up.
It's also nice because Jackendoff is smart, and has spent years developing this theory in response to Psychological, Linguistic, Computational, Evolutionary and Developmental data.