Early bilingual acquisition: the effects of home language typology on learning English inflectional morphology

Bilingual preschoolers come from different home language environments. This presents a challenge in understanding what constitutes “typical” bilingual language development, especially for those learning new structures absent in the home language. This study examined preschoolers’ knowledge of English plural inflections and number agreement and compared the performance of monolingual English speakers with that of bilinguals speaking Chinese (with no inflections) versus home languages with inflections. A two-alternative-forced choice paradigm was deployed on an iPad, with a picture of a single novel object presented next to a picture of five novel objects. Auditory prompts for the novel words included singular (e.g., tep) and plural (e.g., negs) forms, used in sentences. The results showed that monolinguals could comprehend all plurals and singulars tested, bilingual preschoolers speaking home languages with inflections could comprehend all plurals (allomorphs: /s/, /z/, /e{capital schwa}z/, and agreement), but Chinese-speaking preschoolers could only comprehend plural agreement (with the copula are), but not inflectional morphemes. This suggests that bilingual preschoolers’ acquisition of English grammar is more protracted than that of their English-speaking peers, especially for those speaking uninflected home languages. These results point to the need to consider the home language typology when assessing bilingual development.