Child care workers, preschool educators, teachers, speech and language professionals, pediatricians – they all frequently meet up with children who grow up with several languages. The proportion of bilingual children seems to have greatly increased over the last decades. Although we don’t have precise statistics, it is likely that about a fifth of children in the Global North are learning more than a single language. Because there are many thoroughly multilingual societies in the Global South, the worldwide proportion is probably close to 50%.

In spite of the great numbers of bilingual children on our planet, professionals working with children and the general public don’t know all that much about their language development. This limited knowledge has given rise to many myths. Many people believe bilingual children are confused, or that children have to be extra smart to learn more than a single language. Many professionals think that a bilingual environment slows down children’s language development. These myths have very negative effects. They stand in the way of children’s and families’ well-being and threaten harmonious bilingualism.

Fortunately research into early bilingualism has vastly increased in the last 25 years or so. As a result, scholarly knowledge about how children learn two languages has greatly improved. This Element brings that knowledge together. It reviews and summarizes what we currently know about how bilingual children develop their languages in the first decade of life, that is, in infancy, early childhood, and middle childhood.

Children become bilingual at different times of their lives and in different settings. This Element explains how these different circumstances have an effect on how children learn their languages. Many children start learning two languages from birth in the home (Bilingual First Language Acquisition). In early childhood hitherto monolingual children start hearing a second language through daycare or preschool (Early Second Language Acquisition). Yet other hitherto monolingual children may start hearing and acquiring a second language after entering primary school in middle childhood (Second Language Acquisition). All children eventually learn to speak the main language spoken in public life and at school. However, many children do not learn to fluently speak a language that they hear at home but that is not used at school. They may even stop speaking it. Children’s and families’ harmonious bilingualism is threatened if bilingual children do not develop high proficiency in all the languages they encounter in daily life.

Developing good skills in several languages depends on many factors. This Element reviews the factors for each of the first three life stages (infancy, early and middle childhood). The weight of factors dynamically changes as children grow older. However, on the whole, the amount of input in each language, parental conversational practices, and pedagogical approaches play a pivotal role in supporting dual language proficiency and harmonious bilingual development (www.habilnet.org).

Bilingual Development in Childhood by Annick De Houwer is part of the Elements in Child Development series

Image Credits: © Annick De Houwer @ habilnet