Input-output effects in the bilingual first language acquisition of English and Polish

Abstract

Abstract This diary study looks at the acquisition of early words in two bilingual sisters (0;9–2;03.22 and 0;9–1;09.13) exposed to English and Polish from birth. It examines whether their parents’ input recorded on video can explain the proportions of different types of words learnt. Their bias for social words is explained by these words being heard in isolation; that for nouns by competitive proportions of noun types heard in the input. Contrarily, the late acquisition of closed-class items is explained by their high usage rates as part of constructions. Meanwhile, high numbers of early verbs in both children’s Polish are explained by inflected Polish verbs being heard (a) in isolation and (b) at the beginning and end of utterances more frequently than their uninflected English counterparts. These results are discussed within the context of the usage-based theory, with focus on the impact of word types for the acquisition of word groups.