How does grammar emerge for children simultaneously acquiring Basque and Spanish as L1S?

Laburpena

Within the last decades there has been a debate about the grammatical system of children acquiring more than one language as their first languages. These bilingual children in the early stages of the process of acquisition tend to code-switch all the time. Therefore, two main hypotheses have arisen: the Differentiation Hypothesis (Meisel 1989, De Houwer 1995, Paradis & Genesee 1997, among others) and the Fusion Hypothesis (Leopold 1949, Volterra & Taeschner 1978, and others). The first one claims that these children have separate grammars for each of the languages they are acquiring. The second one supports the idea that a plurilingual child creates a unique grammatical system by combining the several first languages. I have studied the utterances produced by 3 year-old Basque-Spanish bilingual children who are simultaneously acquiring both languages, and I have carried out two analyses based on the typological differences between both languages. The basis of the first analysis is the postposition-preposition typological difference, whereas the second analysis highlights the difference between ergative and accusative languages. The data for the analyses have been taken from talkbank databank. These are transcriptions of the conversations held in school classes for a period of 4 months. The results reveal that children seem to have separate grammars for Basque and Spanish from the first stages of acquisition. In any event, this is a work in progress and I am currently analyzing more data in order to find more evidence that supports my conclusion.