Variation in language development : Implications for research and theory

[Extract] Both psychologists and linguists who study language development have typically looked for commonalities across young language learners in babbled sounds, first words and early sentences, and the eventual elaborations of syntax. Their interest in language universals has been largely motivated by the undeniable fact that the ability to learn language is shared by all normally developing human infants. However, the words and sentences of children learning to talk within and across language communities reveal interesting differences as well as overlapping milestones. Consider these two English language learners. At 18 months, Johanna has a substantial vocabulary of single words that label important objects and entities in her world. She can talk about food (banana, apple, cheese), clothing (sock, shoes, hat), animals (birdie, cat), household items (keys, light), and toys (dolly, ball). Non-nominals are fewer: hi, bye-bye, up, down, no. Many of her words are learned and used in the course of naming games that she plays with her parents. Bath time elicits nose, teeth, eyes, ears, face, hair, belly. Picture books are also enjoyed as opportunities for displaying Johanna’s word knowledge.