Parsing Efficiency, Binding, C-Command and Learnability

A principal goal of modern linguistic theory has been to formulate constraints on grammars so as to explain how it is that linguistic knowledge can be acquired. The aim has been to narrow the class of possible grammars so that it is as small as possible, consistent with observed variation in natural grammars. But from the very beginning of the modern study of generative grammar, there has been another “functional” motivation that has been used — though less frequently — to constrain the class of possible grammars. This is the demand of parsability or (in its dual sense), of generability. For example, we might require that natural grammars be amenable to “easy” recognition or generation, in some sense. This demand has actually been explicit since the earliest days of the field, as the following quote from Chomsky’s Morphophonemics of Modern Hebrew [1951] indicates: The criteria of simplicity governing the ordening of statements is as follows: that the shorter grammar is the simpler, and that among equally short grammars, the simplest is that in which the average lenght of derivation of sentences is least.