The goal of this chapter is to understand how SES shapes children's language learning environments and their language development, in the larger context of how socioeconomic status (SES) shapes children's lives and developmental trajectories. The literature provides ample evidence that both the environments in which children acquire language and the rate of children's language development vary as a function of family SES. Environmental differences arise, at least in part, from SES-related differences in the ways in which mothers interact with and talk to their children. Compared to lower-SES mothers, higher-SES mothers talk more to their children and are more responsive to their children's verbalizations (Hoff, Laursen, & Tardif, 2002). Higher-SES mothers use speech more for the purpose of initiating and sustaining conversation with their children and less for the purpose of directing their children's behavior; they also use more complex syntax and a more varied vocabulary in talking to their children (Hoff et a!., 2002; Huttenlocher, Vasilyeva, Cymerman, & Levine, 2(02). SES-related differences in children's language skills are consistently found from at least the age of 2 years (see Arriaga, Fenson, Cronan, & Pethick, 1998; Hoff, in press). The domains of

children's language that differ as a function of SES include the functions to which language is put (e.g., Tough, 1982), the grammatical complexity of speech (e.g., Arriaga et aI., 1998; Huttenlocher et aI., 2002), and vocabulary (e.g., Arriaga et al., 1998).