  So in answer to the question: how do we learn that H2 is better than H1, Chomsky argued that we don't learn this at all! A better explanation of how we all know that H2 is right and H1 is wrong is that we were born knowing this fact. Or, more accurately, we were born knowing a certain principle of UG (the ‘Principle of Structure Dependence’), which tells us that rules like H1 are not worth pursuing, their ostensible ‘simplicity’ notwithstanding, and that we should always prefer rules, like H2, which are stated in terms of sentences' structural properties. In sum, we know that H2 is a better rule than H1, but we didn't learn this from our experience of the language. Rather, this fact is a consequence of our inborn knowledge of UG.