Colin Baker's definition of bilingualism is complex and is in many forms according to his book, "Term bilingualism" is typically used to describe the two languages of an individual when the focus changes to two languages in society the term often used Diglossia. In practice a language community is unlikely to use both languages for the same purpose.
A language community is more likely to use one language in certain situation and for certain functions the other language in different circumstances and for different functions. For example a language community may use a minority language in the home, for religious purpose and in social activity but use the majority language at work in education and then experiencing the mass media.
In order understand current development in second language learning I will brief discuss on how the second language learning was believed to be have learnt during the 1950s 1960s and the 1980s.
Firstly in the early 1950s and early 1960s, theorising about the second language was very was attachment to practice business language teaching. the idea that language teaching methods had to be justified in terms of an underlying learning theory was well established since the pedagogic reform movements of the late nineteenth century according to Howatt 1988. According to Hawatt he Sums the progressive 1950s language pedagogy drew on a version of strurctrculim development by Freis and his Michigan colleagues in the 1940s. Howatt summarise this approach as followers,
The conviction that language system consists of a finite set of 'patterns' or 'structures' which acted as models... for the production of an infinite number of similarly constructed sentences.
The belief that repetition and practice resulted in the formation of accurate and fluent foreign language habits.
A methodology which set out to teach 'the basic' before encouraging learners to communicate...