Although children's use of speech registers such as Baby Talk is well documented, little is known about their understanding of Foreigner Talk, a register addressed to non-native speakers. In Study 1, 4- to 8-year-old children and adults (N = 125) heard 4 registers (Foreigner Talk, Baby Talk, Peer Talk, and Teacher Talk) and predicted who would…

Is "two" ever a plural marker in child language? By some accounts, children bootstrap the distinction between the words "one" and "two" by observing their use with singular-plural marking ("one ball/two balls"). Others argue that the numeral "two" marks plurality before children begin using numerals to denote precise quantities. We tested the…

Until recently, the challenges inherent in measuring comprehension have impeded our ability to predict the course of language acquisition. The present research reports on a longitudinal assessment of the convergent and predictive validity of the MacArthur-Bates Communicative Development Inventories: Words and Gestures (CDI: WG; Fenson et al.,…