The author raises the question of what one can say about the structure of a person's language from a sample of his speech production and urges the calculating of information theory parameters for grammatical constructions. What has to be done is to decide what construction to focus on and what types to recognize as exemplifying that construction. The author and his colleagues have worked out such breakdowns for three sorts of constructions: finite verb phrases, noun phrases, and classical components, and tallied the occurrences of each of these three sorts of constructions for samples of speech collected from 30 children each (age 5, 6, 7, 9, 11, and 13). For all three sets of construction types there are definite increases with age in the 5-13 year span. It is clear that the older children have to do more selecting when they produce the obvious English syntactic categories of verb phrase, noun phrase, and sentence frame. The author regards the best grammar for a child as that which generates the highest H's (the measure of average surprise value of selections from sets of entities with different probabilities of occurrence) and relative H's for his produced speech. (AMM)