Agreement and case are called “apparent imperfections,” rather than basic design features of language (Chomsky, 2000b, p. 111); their virtues in free word order languages are ignored.
But, as we noted, languages use four different devices for conveying semantic relations: phrase structure, linear order, agreement, and case, often deployed redundantly.
It looks as if evolution has found several solutions that ordinarily reinforce each other, with some predominating over others in special circumstances; in the case of language, the balance among them shifts depending on the language?s history, the sentence?s context, or both.
If so, case and agreement are not “imperfections” at all, just alternative mechanisms to the same end as phrase order and hierarchy.
This echoes an earlier suggestion that “In the case of such systems as language or wings it is not easy even to imagine a course of selection that might have given rise to them.
The “What good is five percent of a wing?” argument has long been raised by creationists, and in every case has been answered by showing that intermediary structures in fact are useful (Dawkins, 1986; Pennock, 2000).
In the case of language, pidgins are a key source of evidence.
They are mappings of phonological structure to meaning that lack fixed word order, case, and agreement.
In sum, we find HCF’s case that language is not an adaptation for communication unconvincing.
And the last, in every case to make enumerations so complete, and reviews so general, that I might be assured that nothing was omitted.