Grammar: "Ready to Use" or "Requires Assembly"

My basement flooded last week and in order to improve the drainage I needed to remove my garden shed. As I flipped through a Canadian catalogue looking for a replacement, I noticed that some sheds were virtually ready to use upon delivery while others needed assembly. "Requires two persons and 6-8 hours." It struck me that this distinction in garden sheds has much in common with beliefs about the nature of grammar. There is widespread agreement that adult speakers rely on grammatical representations that include abstract elements such as Noun, Verb, or AUX. Without such abstract categories, we could not continually talk about new things, like the similarity between grammars and garden sheds. But for over 35 years now, there have persisted two very different views of how this abstract adult grammar comes to be.

In the Chomskian view, the human mind is innately provided with a Universal Grammar that includes categories such as Noun and Verb (Chomsky, 1965). Other linguists, however, have not assumed that these categories are available from the outset, and instead have asked how grammatical categories might emerge out of the organizing activities of the human mind (Elman, Bates, Johnson, Kamiloff-Smith, & Parisi, 1996). Is grammar "Ready to Use" or does it "Require Assembly?" Can speech-language patholgists (SLPs) merely open the box, or must we stick around for a while and assist the child in constructing an abstract grammar? It is too soon for a definitive answer, but current research on this topic is intriguing.

Melissa Bowerman (1973) was among the first to caution against assuming too much too soon in children's grammar. She analyzed data from children learning Finnish, and concluded that meaning-based categories such as Agent were closer to the child's competence than meaning-free categories such as Verb. She observed that children's utterances in the early stages were not nearly as productive as a fully abstract system would predict. If children really knew the N + V + N sentence pattern, why was it used with only a small proportion of their verbs? More recently, Michael Tomasello (2000) has taken this vision of an alternative child grammar as the starting point for a new perspective on language learning. He calls it "construction grammar" and it is indeed a theory in which children gradually construct grammatical categories out of instances of particular verbs and sentences.

A Constructivist View of Acquisition

According to Tomasello, language development proceeds through three periods during the preschool years. In the first period, toddlers (under 2:6 or so) combine words using patterns that are lexically specified. Their grammars include virtually none of the high level abstractions such as V, AUX , or PREP, that are key to the adult speaker's language productivity. Instead, toddlers only have one category, Nominals (concrete nouns and pronouns), and their understanding of word combinations is limited to the knowledge that a specific verb can be preceded and/or followed by a Nominal. The resulting grammar, such as it is, consists of patterns such as N + "play" or N + "see" + N. The pattern(s) preferred for a given verb would be the one(s) heard most frequently. Note that grammars of this sort are productive, but to a very limited degree. Each verb is associated with its own specific sentence pattern; only the referents (Nominals) change. The child can put a new noun in the Nominal slot, but there is no further room for creativity.

In the second period, ages 3-4, grammars become more and more abstract. Although the process is not well-understood, new patterns seem to be constructed by analogy. Children see that the relationshipsboth structural and semanticbetween Daddy and fix in the sentence "Daddy fixed the bicycle," are the same as the relationships between Mommy and bake in the sentence "Mommy baked cookies." The construction process is guided by meaning at two levelslexical and combinatorial. For example, when preschoolers construct the transitive sentence pattern N + V + N, they link this ordered string to a causal meaning. Because of this new level of abstraction, four-year-olds can use a new verb in this transitive pattern without ever having heard it used that way, but only if the verb has a causal meaning.