The deep forces that shape language and the poverty of the stimulus

This chapter discusses some of the causal forces that enable young children to acquire language. It demonstrates that these causal forces are not readily apparent in the input that children experience. This discussion of the causal forces of language and the poverty of the stimulus focuses on just a fragment of human language. The chapter discusses four kinds of expressions. In English, these expressions are the words some, any, and or, and question words such as who and what. Although these expressions appear to be unrelated, the chapter shows that they are all cut from the same cloth - they are governed by the same linguistic principles, which determine both their distributional properties and their meanings. Like any and or, linguists have proposed principles that amalgamate information-seeking questions and their statement counterparts. The chapter describes the important role played by cross-linguistic facts as a source of information about the deep forces that shape language.