Simultaneous bilingualism is a form of bilingualism that takes place when a child becomes bilingual by learning two languages from birth.Children who are regularly addressed in two spoken languages from before the age of two and who continue to be regularly addressed in those languages up until the final stages" of language development.Both languages are acquired as first languages. This is in contrast to sequential bilingualism, in which the second language is learned not as a native language but a foreign language. Studying bilingual acquisition is important because it may have real effects on academic performances for bilingual children in school. Research has shown that vocabulary size is an indicator of academic performance and literacy.