This study concerns simultaneous bilingual acquisition (2L1) of Swedish-Brazilian children growing up in mixed-lingual families in Stockholm, with Swedish as their dominant language. Earlier studies on this language combination were not found. Not even were there any studies considering 2L1 children of the same age group as our main subjects (Anna 7;7,3–9;1,30, Maria 6;1,16–6;11,11). An analysis of their acquisition of Brazilian Portuguese (BP) as a weaker language (WL) was carried out in a Generative Grammar approach, mainly through the selective theory of language acquisition. The corpus consists of interviews with 2L1 children in a semi-longitudinal registration of their production. The focus of this analysis lies on the observation of three domains of BP grammar that differ morpho-syntactically from Swedish: verb inflection; VP as minimal responses; NP number and gender agreement. Three main research questions were formulated: 1) Are the simple and robust structures, provided by domestic input enough for triggering the functional categories (FC) of their WL? 2) If the FCs are activated, do they develop in the same sequence as a WL as they would in BPL1? 3) If the 2L1 children show any deviations in acquiring the grammar of their WL, is it possible to distinguish any influence from Swedish? To answer these questions a contrastive study was carried out, comparing the acquisition of BPWL with studies on 2L1 and BPL1 acquisition. The results show that the domestic input is enough for triggering the grammar of the WL, and that it was triggered and developed through a similar procedure to that of BPL1, although delayed. Contact with BPL1 input in Brazil was necessary to activate the children’s oral production. When using VPs for minimal responses it requires more than domestic input, and the influence of Swedish was reflected in the subjects’ use of sim ‘yes’ instead of VPs, as in this case grammar enters the domain of discourse at the syntax/pragmatics interface.

This case study investigates the acquisition of Russian in a language contact situation. It examines a simultaneous Swedish-Russian bilingual child born and raised in Sweden. Qualitative analysis is provided from age 1;4 to 8;5 focusing especially on the earliest stages (before the end of the critical period at 4;5). The aim was to investigate (a) whether the child reaches the same milestones as monolingual children, (b) whether there is evidence that two separate linguistic systems have been developed, (c) whether the child’s grammatical competence in both languages might be qualitatively different from that of monolingual children and (d) whether there is interaction between the languages. The hypothesis tested is that ample input is needed to construct and develop two linguistic systems on a native-speaker level. The main result is that the two linguistic systems do not develop independently from each other; rather, 2L1s develop in permanent interaction where the weaker language – Russian – happens to be influenced by the stronger one – Swedish. The bilingual environment per se might lead to decreased structural complexity in the weaker language. Language dominance is viewed as a major determiner of cross-linguistic effects. This could lead to the development of a new individual variety of Russian (outside Russia).   The results confirm the hypothesis that, even though there was exposure to both languages from birth onwards, the amount of input in the weaker and grammatically more complex language (Russian) received before the cri­tical period was not enough to completely develop full native command of it. The lack of input has an impact on the acquisition of morphology: some morphological categories may have been set randomly or not at all. The structures observed are more ty­pical of L2 than L1 ac­quisition. Morphology may be considered a vulnerable domain since complex mor­phological rules in Russian cannot develop with­out ample input.