Abstract

The Input language provided to young learners play important roles in their language acquisition. Caregiver speech draws and sustains learners’ attention, and this sustained attention may facilitate word acquisition. The role of caregivers’ speech quality in sustaining learners’ attention and facilitating word acquisition has not been investigated in Korean. Twenty-four Korean mothers’ speeches provided for their 15-20-month-olds were analyzed to examine how the relationships between speech quality and sustained attention relate to concurrent and later vocabulary acquisition. Unlike English findings, syntax predicted later vocabulary acquisition, instead of the referential nature or communicative intent. Specifically, declarative use elicited sustained attention and positively predicted vocabulary growth, whereas sentence fragments were less likely to sustain attention and negatively predicted word growth. Interestingly, however, a similar proportion of overall referential speech was observed to that of English, raising the possibility that Korean caregivers may be less likely to omit referent mentions in infant-directed speech.