Phonological memory and the development of vocabulary and grammar in young Spanish-English bilinguals

This study tested the hypotheses that phonological memory contributes to vocabulary and grammatical development in young Spanish-English bilinguals, and that the relation between phonological memory and both vocabulary and grammar is language-specific. Phonological memory skill was the percentage of consonants correctly repeated (PCC) in English, and Spanish Nonword Repetition (NWR) tasks at 22 months. Vocabulary size and grammatical complexity were measured at 25 months using the English and Spanish versions for the MacArthur-Bates Communicative Development Inventories. Nonword repetition accuracy was significantly related to both subsequent vocabulary size and grammatical complexity within and across languages after controlling for the percentage of input in English. The relations were not significantly higher within than between languages. The results suggest that in these young Spanish-English simultaneous bilinguals phonological memory is a language-general ability that contributes to the development of vocabulary and grammar in both English and Spanish.