You must be perfectly fluent in both languages to be considered bilingual.
While there is a common expectation that one should be able to read, write and speak a language well in order to be considered bilingual, there is a wide range of normal. The language outcome of a bilingual child often relies on what function(s) each language serves for the child. If a child primarily speaks Spanish at home with family members and attends school in English, it is likely that s/he will speak Spanish fluently, with use of slang and informal grammar, and will read, write and speak English both formally and informally, thanks to schooling in that language. A child from the same background who is lucky enough to attend a bilingual school will probably be able to use both languages formally and informally. However, as an adult, one language may still be dominant, depending on the language used in the workplace and in social activities.
Learning two languages is confusing for a child.
Watching a child learn to talk can be an amazing thing. A child may appear to hear a word once and then use it the next day. While it may seem like a heavy load for a child to learn two languages at once, children do this easily. In fact, research has indicated many benefits of bilingualism, including improved information processing, learning and reduced age-related language decline later in life.
Language delays are common in children learning more than one language.
A child learning two languages may engage in code-switching. Code switching refers to using a mix of two languages, like a child saying “I want sopa (soup).” This is a normal aspect of bilingual language development, and may even be observed by adults in the child’s environment (e.g., “Spanglish”). A child may also have better grammar in one language than another (especially the language used at school). This does not mean the child is delayed, but if knowledge of grammar and formal language are important to a family, the child may need direct help in that language. However, if you notice mistakes or difficulty acquiring and/or using both languages, something more may be going on. In this case, don't hesitate to contact a local speech-language pathologist for help.
If your child isn’t using both languages, s/he isn’t learning both.
Children may show a preference for one language for a variety of reasons. If a child’s English speaking friends are over, he may be more likely to use English instead of Japanese with his mother. If a child is attending a French language immersion school but has primarily used English at home with her parents, she may be unwilling to “practice” French with her Mom. If you are concerned about your child using one language less than the other, pay attention to how your child appears to understand each language. Does he understand directions in both languages? Will she laugh at jokes in both languages when watching a cartoon?
A child will be less successful in school if the dominant language isn’t used at home.
The dominant language refers to the language used in the community. In the United States, this is typically English. Parents may be concerned that if they don’t “prep” their children to use English in school, they will fall behind. However, there are many positive aspects to using the L1 at home. In addition to the benefits described before, parents will likely communicate cultural values and family heritage through their first language. Knowledge of the heritage language may help a child better connect to relatives who don’t speak English. Parents may also provide a better language model using appropriate grammar when speaking in their first language (depending on their knowledge of the L2).
Next time, I’ll talk about how to support your child’s language development when learning multiple languages, and share my personal experience growing up bilingual.