I agree that Language is not the only way of capturing thoughts. We usually have a photographic representation of what we see in our heads. But we use language to bind the various abstract representations together. For example, you have a abstract representation of your friend John and the same for a grocery store. So when you think the following “When John goes to the grocery store, I’ll run away with his bike” – you don’t visualize John actually walking into the grocery store and you running away with his bike. This entire thought sequence is processed as language in your head – try it out to see what I’m trying to say. Yes, thoughts flash miraculously in our head – and I dont have an explanation for that – but the onus is not how they were initiated but rather in what form are they initiated. You are right in saying that Language is not the only way (or probably even the right) way of representing thoughts but if we can build machines which use language it would be easier for Humans to understand the output produced by such machines.

Lets answer these questions,
Is Language the only way of capturing the thoughts that come to one’s mind? I think NO. Language sure is one way of representation, but it is not the only way. So by modelling a language we might be able to track the thoughts that were “expressed” by the person. But the possibility of some other thought came like a flash in one’s mind he just did some gesture (looked some place, read something, or may be touched something) is pretty high, which intern triggered and chain of thoughts that resulted in a sentence that he/she expressed to the world again (via Twitter, if I understand your plan correctly). We surely have two of these thoughts but we do not have the behavioural or thought sequence that could be more important in understanding the cognitive sequence. The point I am trying to make is that Language surely has a potential of expressing things around but the assumption that all of us will express every thought that comes to one’s mind is a little bit of a over kill I think.

Second, grammar of language “in use” keeps changing. If you don’t believe me, check for yourself the language used by kids today did you use something remotely close to this? I am not talking about the “Wren and Martin” text bookish language used in the technical papers, I am talking about the common man of tomorrow, who is hell bent up on using the phonetic acronyms, mixing two or more languages that he or she knows in to his or her discourse and is more keen on expressing the thoughts. Again, the point is language is a changing phenomena, it changed less frequently in the past but now mixing of cultures and inter mingling of people from various places and for many more reason that might be beyond me. But, I think while modelling a language the very assumption that it has a grammar is misleading. I DO NOT say language has no grammar but for our purpose of analysis it is kind of irrelevant. So I would suggest use the bag of words approach to define statistical models for language. I think there are enough papers and other technical articles on this. These are just my thoughts, and I will be happy to know if someone disagrees with them and wishes to discuss it.

The methods by which these meta-production rules are learned, modified, and adapted still eludes me.