It is hard to imagine a world without language. For social animals like human beings, language can almost be considered a necessity to survive. Regardless of location or context, some form of language constantly surrounds an individual. However, like we do not consciously think about breathing or about air to be able to breathe, we do not consciously think about producing words or sentences to be able to use a language. The mystery of language development is fascinating in and of itself. Children acquire language without formal instruction, and may even develop language without exposure to an existing form. How does the average human effortlessly master one language by early childhood? An even more fascinating question is one of bilingualism-humans seem to master two languages just as easily if they are exposed to both languages early in life. Various researchers have continuously investigated this extremely intriguing issue. Though there have been countless studies based on numerous theories, the mystery remains only partially solved. One issue that has been the focus of these heated debates is about the process and structure of bilingual language development.
             Until recently, the prevalent belief was that bilingualism has a negative effect on children's language development. However, based on significant research, the belief seems to have shifted dramatically. The current belief holds that bilingualism is advantageous over monolingualism in several aspects of development. Perhaps the most interesting issue in bilingualism studies is of how the two languages are organized and structured in the human mind.
             There is much evidence that during infancy, bilingual children mix elements from both of their languages. The common but not necessarily accurate assumption that stems from this finding is that these children possess an "undifferentiated or unitary underlying language system" (Genesee 1989). Apparen...