Moreover, functional morphemes such as articles, auxiliaries, and af?xes are also part of the lexicon (since each involves a pairing between a sound and some other information, both of which are speci?c to the particular language), yet the information they encode (case, agreement, ?niteness, voice, and so on) is continuous with the information encoded by syntax.
Even in the case of learning nouns, there are reasons to suspect that children treat facts and words in different ways.
English relies heavily on order and constituency, but has vestigial agreement and no case except on pronouns.
The Australian language Warlpiri has virtually free word order and an exuberant system of case and agreement; Russian and Classical Latin are not far behind.
Many languages use the systems redundantly, for instance German, with its rich gender and case systems, moderate use of agreement, and fairly strong constraints on phrase order.
A case marker may not contain another instance of a case marker; an article may not contain an article; a pronoun may not contain a pronoun, and so on for auxiliaries, tense features, and so on. HCF cite none of these devices as part of language, although each weakens the hypothesis that the narrow language faculty consists only of recursion.
Syntax: Case, agreement, pronouns, predicate-argument structure, topic, focus, auxiliaries, question markers, and so on, are not discussed by HCF.
We conclude that the empirical case for the recursion-only hypothesis is extremely weak.
For instance, when Chomsky says that Minimalism does without deep and surface structures, he means only that these structures are not singled out as representations to which constraints such as the Projection Principle or Case Filter apply.
By similar logic, a system for “talking to oneself” would not need phonology or phonetics tuned to the properties of the human vocal tract, it would not need linear order or case or agreement, and it would not need mechanisms for topic and focus, all of which presuppose that information has to be coded into a serial, perceptible signal for the benefit of listeners who currently lack the information and have to integrate it piecemeal with what they know.