The acquisition of ergative case in Warlpiri
Ellipsis of core arguments in Warlpiri reduces the contexts in which children hear ergative case forms. The chapter discusses this and other possible factors that might impact on children’s acquisition of ergative morphology. Two sets of data are discussed. Naturalistic data show that by the age of three years children use ergative case in the appropriate contexts but have not mastered when to use the different allomorphs. At age four there are examples of ergative forms being used appropriately for agreement and instrumental case. The use of ergative morphology was not extended to non-ergative verbs and not restricted to past tense. The second set of data is based on adult and child narratives elicited with two picture books. It illustrates the contexts for using ergative morphology and the variability in whether subjects are included or omitted within and across age groups.