Infants discover English suffixes allomorph by allomorph.

Abstract

Recent research has shown that 6-month-olds relate novel words suffixed with -s, like babs, that are embedded in passages, with just the stem bab, demonstrating an early sensitivity to morphological relatedness. This study builds on these findings by investigating the role of allomorphy in early morphological acquisition. We tested whether infants relate novel words suffixed with [-z] and [-s] allomorphs of the -s suffix and their stems. We find that English-learning 6-month-olds relate novel words suffixed with the [-z], but not [-s], allomorph with stems, providing evidence for an acquisition trajectory where infants discover morphemes one allomorph at a time.