Two-part vowel modifications in Child Directed Speech in Warlpiri may enhance child attention to speech and scaffold noun acquisition.

Study 1 compared vowels in Child Directed Speech (CDS; child ages 25-46 months) to vowels in Adult Directed Speech (ADS) in natural conversation in the Australian Indigenous language Warlpiri, which has three vowels (/i/, /a/, /u). Study 2 compared the vowels of the child interlocutors from Study 1 to caregiver ADS and CDS. Study 1 indicates that Warlpiri CDS vowels are characterised by fronting, /a/-lowering, f o -raising, and increased duration, but not vowel space expansion. Vowels in CDS nouns, however, show increased between-contrast differentiation and reduced within-contrast variation, similar to what has been reported for other languages. We argue that this two-part CDS modification process serves a dual purpose: Vowel space shifting induces IDS/CDS that sounds more child-like, which may enhance child attention to speech, while increased between-contrast differentiation and reduced within-contrast variation in nouns may serve didactic purposes by providing high-quality information about lexical specifications. Study 2 indicates that Warlpiri CDS vowels are more like child vowels, providing indirect evidence that aspects of CDS may serve non-linguistic purposes simultaneously with other aspects serving linguistic-didactic purposes. The studies have novel implications for the way CDS vowel modifications are considered and highlight the necessity of naturalistic data collection, novel analyses, and typological diversity.

Voice onset time and constriction duration in Warlpiri stops (Australia).

This paper presents a first detailed analysis of the Voice Onset Time (VOT) and Constriction Duration (CD) of stops /p t ʈ c k/ and flap /ɽ/ in the Indigenous Australian language Warlpiri as spoken in Lajamanu Community, in Australia's Northern Territory. The results show that Warlpiri stops are realised as voiceless, long-lag stops word-initially, as well as word-medially, where /p t k/ are also characterised by CDs in excess of 100 ms. This is similar to what has been reported for Kriol, and for the emerging mixed language Light Warlpiri, also spoken in the community, and by some of the participants. The results indicate that Warlpiri does not obligatorily make a word-medial distinction between stops orthographically represented by 'rt' and 'rd', which have previously been argued to be realised as /ʈ/ and /ɽ/, respectively, at least in some varieties of Warlpiri. Finally, the results also suggest that the realisation of word-initial Warlpiri flap /ɽ/ is highly variable, potentially resulting in a near-merger with /É»/.

Competition between word order and case-marking in interpreting grammatical relations: a case study in multilingual acquisition.

The study examines strategies multilingual children use to interpret grammatical relations, focusing on their two primary languages, Lajamanu Warlpiri and Light Warlpiri. Both languages use mixed systems for indicating grammatical relations. In both languages ergative-absolutive case-marking indicates core arguments, but to different extents in each language. In Lajamanu Warlpiri, pronominal clitics in a nominative-accusative pattern also indicate core arguments, and in Light Warlpiri word order in a nominative-accusative pattern partially does so. The study asks which sentence interpretation strategies children rely on most, when they learn to rely on them and whether cross-linguistic influences are seen. Children aged 5;0, 7;0 and 9;0 and adults saw paired, animated events simultaneously on video and heard a transitive sentence spoken. The participants pointed to the event depicted by the sentence heard. Adults used a case-marking strategy consistently in both languages. Children initially used both case-marking and word order strategies, but used case-marking more often as age increased.