I’ve heard it said that children have a remarkable capacity to learn new languages, well I’m kind of a strange case in point. My father is Australian and my mother is Finnish, and I was born in Toronto Canada so the first language I spoke was English, after my parents separated, I was about 3 or 4 years old and my mother took me to live in Finland, and I learned to speak Finnish within a matter of a few months. I totally forgot English except for a few words that my mother still used when speaking to me. When I was 4 going on five, my Finnish grandmother died and my mother remarried, I didn’t get along with my stepfather so it was arranged for me to fly to England where my father was living, and I was to live with him. I had no one to speak Finnish, with so I quickly reverted to speaking English and forgot almost all of my Finnish, which I was fluent in a child’s level. Now here’s the strange thing when I was living in Finland before my grandmother died, I remember the house being full of young women whom she was interviewing as house keepers / nannies. I remember overhearing the conversation she had with one of the girls, and it went thus: Grandmother –“Can you bake bread?” Girl –“ I know how to make Sugar Cake." Grandmother–“No No, Bread!” Now the thing that’s strange about this conversation is that these were two people who didn’t speak English at all, the interview was conducted it in Finnish, but I remember it word for word in English. Saying that I do remember one key word was spoken in Finnish, and that was the word, “Bread” which in Finnish is “Leipặ” I heard “Leipặ” in the place of bread but every other word in that conversation was remembered in English. Are there any studies that can explain this sort of language / memory transference?
My kids are totally bilingual (both languages like native speaker, third language like second language) and I am bilingual also, but I learnt the second language properly as a young adult. I used to speak almost fluent Maltese and French but they lapsed through lack of exposure, much as you 'forgot' Finnish. The brains of second language users and bilingual speakers work differently from 'normal' people. It also depends on the age you were exposed to the languages--usually if it's after 3 the brain does not function totally as a single language speaker. I don't know how technical or in depth you want to go, but these references are concerning the brain and vocabulary acquisition and retention in second language learners and true bilinguals: Jiang, N. (2004). Morphological Insensitivity In Second Language Processing, Applied Psycholinguistics, 25 : 603-634. Kroll, J. F. et al. (2002). The Development of Lexical Fluency in a Second Language. Second Language Research, 18 : 137. Köpke, B. (2004). Neurolinguistic Aspects of Attrition. Journal of Neurolinguistics. 17 : 3-30. McDonald, J. (2006). Beyond the critical period: Processing-based Explanations for Poor Grammaticality Judgment Performance by Late Second Language Learners, Journal of Memory and Language, 55 : 381–401. Ullman, M. T. (2001). The Neural Basis of Lexicon and Grammar in First and Second Language: The Declarative / Procedural Model. Bilingualism: Language and Cognition, 4 (1): 105-122. I'm giving these as references, not links, so I hope that doesn't breach forum regulations--I don't think it does. You may not find all of them online, though.
Children have an aptitude to learn anything. There was a social study where a girl spoke to 5 different people at a park everyday. They each spoke to her in a different language. By the time she was 5 she was fluent in conversation in all five languages as well as her native tongue, English. As finish is a Scandinavian language, I'd always thought bread would have been spelt "Leipää". I always thought ă was a letter from places like Romania. I guess you learn something new everyday. As for transference... In my experience, whatever your mind thinks is what your mind will process other languages in. When you hear a new word you will automatically associate it with words that sound similar in your own language. I suppose if you remember something vividly but forget the language it was spoken in you will just changed the language and keep the meaning. Sometimes I have dreams in what seem to be languages that I can't even speak. Strange how the mind works, no? ^^