Bilingualism

People may become bilingual either by acquiring two languages at the same time in childhood or by learning a second language sometime after acquiring their first language. Many bilingual people grow up speaking two languages.
The exposure must involve interaction; a child growing up in an English-speaking household who is exposed to Spanish only through Spanish-language television will not
become a Spanish-English bilingual, but a child who is regularly spoken to in both English and Spanish will. Children who hear more than one language virtually from birth are sometimes referred to as “simultaneous bilingual”, whereas those who begin to learn a second language later are referred to as “sequential bilingual”

It is also possible to learn a second language sometime after early childhood, but the older you get, the harder it is to learn to speak a new language as well as a native speaker. Many linguists believe there is a “critical period”. The critical period refers to the idea that the ability to acquire language is biologically linked to age. The hypothesis claims that there is an ideal “window” of time to acquire language in a linguistically rich environment, after which this is no longer possible. Hence, the first few years of life is the crucial time in which an individual can acquire a first language if presented with adequate input. If language input does not occur until after this time, the individual will never achieve a full command of language, especially grammatical systems.

Research has shown that bilingualism is beneficial for children’s development and their future. Children exposed to different languages become more aware of different cultures, of other people and of other points of view. According to these linguists, knowing a second language actually benefits a child's cognitive development. They also state that if the child comes from a family that has recently immigrated to the U.S., the family may speak other language than English at home and may still have strong ties to their ethnic roots. In this case, being able to speak the language of the family's ethnic heritage may be important for the child's sense of cultural identity. To be unable to speak the family's language can make a child feel like an outsider within his or her own family; speaking the family's language gives the child a sense of identity and belonging.