Language development

Encyclopedia of Psychology, Apr 06, 2001 by Jill De Villiers, Ph.D.

Debate has raged over how significant this finding of universal semantic relations is for the study of grammatical development. On the one hand, it might mean that building a grammar based on meaningful relations is a universal first step for language learning. On the other hand, there is the larger problem of how the child builds a grammar that resembles the adult's, because for true linguistic competence, the child needs to build a theory out of the right components: subjects, objects, noun phrases, verb phrases, and the rest. These abstract categories do not translate easily into semantic relations, if at all. To succeed at analyzing or parsing adult sentences into their true grammatical parts, the child must go beyond general meaning. The alternative interpretation of the findings about the first sentences is that children all over the world are constrained by their cognitive development to talk about the same ideas and that their doing so need not mean that their grammars are based solely on semantic relations. So the semantic analysis of children's early sentences offers fascinating data on the meanings children express at that age, but it is less clear that these semantic notions are the components out of which children's grammars are constructed. A weaker hypothesis about the role of semantics in the learning of grammar is that perhaps children exploit the correlation between certain grammatical notions, like subject, and certain semantic notions, like agent, to begin parsing adult sentences. The child could then proceed to analyze sentences by knowing already:

a. the meaning of the individual words

b. the conceptual structure of the event, namely that dog is the agent; bit is the action.

Some have proposed that the child may have some further, possibly innate, "hypotheses" that guide his code-cracking:

c. actions are usually verbs

d. things are usually nouns

e. agents are usually subjects.

Semantic notions then become vital bootstraps for the learning of grammar.

What is missing from the two-word stage are all the modulations of meaning, the fine tunings, which add immeasurably to the subtlety of what we can express. Consider the shades of meaning in the following sentences:

Not all languages make these distinctions explicitly, and some languages make distinctions that English does not. In the next stage of development of English, the extra little function words and inflections that modulate the meaning of the major syntactic relations make their appearance, though it is years until they are fully mastered. For English, it is common to measure the stage of language development by counting and then averaging the morphemes (words and inflections) in a child's set of utterances, and refer to that as the mean length of utterance (MLU). The inflections are surprisingly variable in children's utterances, sometimes present and sometimes absent even within the same stretch of conversation. According to psychologist R. Brown, "All these, like an intricate sort of ivy, begin to grow up between and among the major constituent blocks, the nouns and verbs, to which stage I is largely limited."