The nature of language knowledge
Language development is even more impressive when we consider the nature of what is
learned. It may seem that children merely need to remember what they hear and repeat it
at some later time. But as Chomsky1
pointed out so many years ago, if this were the
essence of language learning, we would not be successful communicators. Verbal
communication requires productivity, i.e. the ability to create an infinite number of
utterances we have never heard before. This endless novelty requires that some aspects of
language knowledge be abstract. Ultimately, “rules” for combining words cannot be rules
about particular words, but must be rules about classes of words such as nouns, verbs or
prepositions. Once these abstract blueprints are available, the speaker can fill the “slots”
in a sentence with the words that best convey the message of the moment. Chomsky’s
key point was that since abstractions cannot ever be directly experienced, they must
emerge from the child’s own mental activity while listening to speech.