HOW WE LEARN A LANGUAGE
Our survey of language has revealed it to be so complex that one might wonder how mere children could acquire it. But as we will see now, not only can infants learn language: They are vastly better at doing so than even the wisest adults. They recog-nize many words before they can even walk. The rate of word learning rapidly acceler-ates to about 3 a day in toddlers, to 5 or 8 or so a day in the preschool years, and to 10 to 15 words a day throughout childhood and early adolescence (P. Bloom, 2000; S. Carey, 1978). The upshot is a vocabulary of about 10,000 words by age 5 and 65,000 or so by adulthood. Late in the second year of life, toddlers start to put the words together into little sentences—“Throw ball!” “No mommy eat!”—making us poignantly aware that another human mind is among us. How is this remarkable achievement to be explained?