Language transfer or code-switching as a part of learning a new language         

Language acquisition in a bilingual setting in children and metalinguistic awareness in children 

A child can transfer her knowledge of language A to language B subconsciously. This happens when the child tries to govern the new language with the help of the already acquired patterns and structures. This transfer (of rules) can either be a positive  transfer (meaning that the applied rules work in both languages) or a negative transfer (meaning that the applied rules do not work in the other language). So language transfer is a tool for Luca to communicate in English (her “most recently added” language) with the help of already existing mental representations. The same goes for code-switching, or simply “mixing” different languages while speaking, as it is a means for Luca to freely communicate with the vocabulary that is available to her. In her case, she communicates in English while filling in words in Portuguese (Cummins, 1980) (Cummins, 1986).