Language consists of so many complex systems, and it is learned so early, that it is difficult to explain how children manage the task. Some psycholinguists have proposed that language is learned by special genetically programmed procedures that are unique to language learning (e.g., Chomsky, 1968; Pinker, 1994). Others contend that the general analytic capacity of the human brain is such that even complex language rules can be worked out without any innate knowledge or special language acquisition procedures (e.g., Karmiloff-Smith, 1992, 2000). Regardless of which view is correct, experience with one’s native language must be critically important. Recognizing the importance of experience raises two questions: First, how much exposure to language is necessary, and second, are there particular language experiences that can facilitate the process of learning?

Researchers have only scratched the surface in addressing these questions. Two domains in which both the quantity and the quality of experience have been linked to quality of learning are semantic development in the learning of vocabulary, and pragmatic development in the production of narratives.

Although most 5-year-olds know enough vocabulary to communicate about everyday things, there are large individual differences among children in the size of their vocabularies. In recent years, it has become clear that vocabulary size is a key predictor of later literacy and success in school. Even if children with relatively small vocabularies are reading at grade level by the end of second grade, they are likely to fall behind in reading starting in third grade when reading comprehension begins to depend more and more on the breadth of a child’s vocabulary (Senechal & LeFevre, 2002). It has also become clear that children’s vocabulary is related to home and preschool environment (e.g., Cunningham, Stanovich, & West, 1994; Senechal & LeFevre, 2002; Weizman & Snow, 2001).

The amount and kind of language experience children have with adults, in parent–child conversations and in joint book reading, are linked with children’s vocabulary. In one study, researchers made monthly visits for over 2 years to the homes of children whose families were either poor and on welfare, lower middle class (mostly in blue-color occupations), or upper middle class with at least one professional parent (Hart & Risley, 1992, 1995). All of the parents were actively involved with their children, playing with them, expressing affection, providing them with toys, and so on. But there were marked differences in how much the three groups of parents talked to their children right from the start. (Children were about 9 months old at the beginning of the study.) In a 100-hour week, a toddler in a professional family might hear 215,000 words on the average; in a lower-middle-class family children heard about 125,000 words; and in the poorest homes about 62,000. All of the children learned to talk on schedule, but the differences in parental input were correlated with children’s vocabulary measures by age 3; children who heard the most language performed best. The content of parents’ conversations with their youngsters also differed. Those who spoke with their children most tended to ask more questions and elaborated more on topics of conversation. Parents who spoke with their children the least tended to utter more prohibitions. Even when the researchers looked within a single socioeconomic group, so that social class was not a factor, children whose parents talked with them more had the most advanced vocabularies. From this and many other studies, it appears that, regardless of social class, the quantity and quality of parent–child conversation can be a significant factor in vocabulary expansion.

Children’s narrative skills may also be tied to the kinds of language opportunities that parents and other caregivers provide. Consider how different the narrative skills of two 5-year-olds in the same classroom proved to be. Both children were retelling a story they were told about a boy’s trip to a grocery store. Both children were clearly familiar with all of the details of the story, having successfully acted it out with dolls and other props.

First Child: John went to the grocery store. He got a cake for his grandmother’s birthday party. And he paid the clerk and ran home.

Second Child: He got cake and he ran home. (Feagans & Farran, 1981, p. 723)

Several studies have found that narrative skill differences like these are connected to the way that mothers converse with their children. If they use an elaborative style, engaging in lengthy discussions about children’s past experiences, providing lots of details, asking questions and encouraging children to provide details as well, their children’s narratives tend to be more adequate and informative (e.g., Reese & Fivush, 1993). An interesting twist is that mothers who engage their children in this kind of high-quality narrative practice also have children who remember past events in their own lives better (e.g., Boland, Haden, & Ornstein, 2003; Haden, Ornstein, Eckerman, & Didow, 2001). In one study, after 3-year-olds visited a museum with their mothers they could remember only what they had actually talked with their mothers about during the trip (Tessler & Nelson, 1994). Discussing an event with preschoolers either before, during, or after it actually happens benefits children’s later memory of it (McGuigan & Salmon, 2004). Katherine Nelson (1993b, 1996) has proposed that narrative practice is a key ingredient in the development of autobiographical memories. We are all familiar with the phenomenon of infantile amnesia, the difficulty we have remembering events in our lives earlier than about our 3rd or 4th year. There are probably many factors that contribute, but perhaps one is that our early experiences occur before we have much mastery of language. Nelson argues that it is the mastery of narrative language that is particularly important. When we tell our own life experiences in conversation with others, we also learn to encode stories in language form, a form that is well suited for later recall. In a way, talking out loud about our experiences teaches us not just how to tell stories but how to remember them as well. Nelson’s view of how autobiographical memory develops is consistent with the ideas of a highly influential psychologist and educator, Lev Vygotsky, who was a contemporary of Piaget and who emphasized the importance of social experience in many aspects of cognitive development.