Worldwide, it is estimated that there are more second language speakers of English than native speakers, and that there are as many bilingual children as there are monolingual children.
Whether bilingualism is a necessity or a choice, it can have many benefits, as long as there is sufficient support to maintain the languages learned.
When comparing bilingual to monolingual subjects, studies have reported:
Better ability to focus attention on relevant information and ignore distractions
Better planning and solving complex problems
Greater access to people and resources
Higher employment rates and incomes
Diminished effects of aging on the brain
Delayed onset of dementia
Some cognitive advantages of bilingualism depend on the individual’s level of proficiency in his languages, ie. The more proficient the individual is, the more benefit he/she will have long term.
Most bilinguals have a ‘dominant’ language, a language of greater proficiency. This can change with age, circumstance, education, social network, employment, and many other factors.
Exposure to more than one language does NOT cause delays in language development and does NOT slow language growth. Language outcomes need to be measured appropriately and account for all of a child’s linguistic systems.
Children with speech and language disorders can learn two languages. Switching over to monolingualism does not help a child overcome a speech or language dosirder. It only creates a monolingual child with a speech or language disorder.
Language development can be typical or atypical irrespective of the number of languages the child is exposed to.