Additive vs. subtractive bilingualism: Language input and language attitudes in bilingual development

Author: Dr Zvjezdana Vrzić

Published on 14 January 2016

Two languages of a bilingual person can be either best friends or worst enemies: they can support and enhance each other’s growth or they can be in competition and one language develops at the expense of the other. Bilingualism scholars refer to these two scenarios as cases of additive and subtractive bilingualism.

Many parents and, even, teachers wonder if learning two languages in early childhood somehow reduces the opportunity for any one language to be learned fully. In other words, they fear that bilingual language learning may be inherently subtractive. Most of us know people who have been fluent and balanced bilinguals since childhood. From the point of view of an individual’s cognitive abilities for language learning, there are no real obstacles to the development of fluency in two or more languages: for example, the human brain doesn’t present any storage limitations and a child learning two languages at the same time doesn’t have any difficulties with the separation of the languages. Providing a learner is exposed to a rich and varied language input in both languages, bilingual language learning will be successful.

While language learning is driven by input, in order to acquire a language we do not have to be exposed to it one hundred percent of our learning time. Children who are exposed to a second language for a half of the time or less – down to a minimum of around twenty to thirty percent – become bilinguals. This is so because language learning requires exposure to a “critical mass” of language data in order to be successful. To learn a word or a structure we need to hear it used a certain number of times. There are differences in how much input is needed for the acquisition of different words and structures; their abstractness or structural complexity are among the factors influencing this. Three times may not do it, but ten or fifteen times may. However, once a word or structure is learned, additional exposure to it doesn’t make a difference any more, which, conveniently, frees up the time for the learning of other languages. Such language learning mechanisms make bilingual language learning inherently additive.

It may happen, nevertheless, that the learning of the second language hinders the continued development of the child’s first language. So, in some cases, childhood bilingualism is indeed subtractive; the second language becomes the child’s dominant language, while his or her first language develops at a slower rate, stops developing at a certain age or is pushed completely out of use by the dominant language. Around the world, immigrant children and children belonging to different ethnolinguistic minorities experience this decrease in development or even loss of their heritage language when they start school. Perfecting the school language becomes a priority and the minority language loses out. The school language is also powerful and prestigious, as it is also typically the language of the wider society, associated with social mobility and social acceptance. This latter factor is particularly applicable for children and youth who do not like to be perceived as different from their peers and friends. For this reason, even strong minority languages, such as Italian in Croatia, which come with significant cultural prestige and institutional support, may be fighting for their place in children’s and youths’ lives.

Skeptical or negative attitudes of the society, teachers, parents, and even children themselves toward bilingualism and the minority language – and they have to do with the questioning of its practical and cultural value – are the key ingredient of this common development. The wider society is often more concerned with the issue of whether minority language speakers are learning the society’s dominant language. This is often so in spite of the fact that the majority language is learned almost without fail due to practical needs, the wide reach of the media and education, the natural processes of social integration, and, often, the pressures of the monolingual language ideology, common in nation-states. However, it is neither desirable nor necessary for the welcome fluency in the majority language to be accompanied by the loss of bilingualism, that is, by a shift to an exclusive use of the majority language and abandonment of the heritage minority language.

Wallace Lambert (Lambert, 1975) was among the first to discuss the difference between subtractive and additive bilingualism and the relevance of social attitudes for these two dramatically different outcomes of bilingual development and use several decades ago. As the well-studied examples from his native Canada show, additive bilingualism is rather easy to attain in bilingual schools geared toward majority populations learning a second language, such as those that serve English-speaking children being educated in French-English bilingual immersion programs. Students come out of these programs fluent in both their first and their second language. There is no reason why this enriching experience couldn’t be had by children speaking a minority language. Dual language programs in the United States, for example, create such opportunities for both minority and majority language children there. Mother tongue education, offered to national and indigenous minorities in various European countries, including in Croatia, and elsewhere in the world, which incorporates majority language classes, is another successful bilingual education format.

When such programs are not available, and even when they are, there are other ways to support the development of healthy, enriching bilingualism in a child’s life. One of the key factors is for families and communities to cultivate and pass on to their children positive attitudes toward the minority language. They are reflected in the will to use the minority language in everyday interactions and in the determination to nurture its social role in families and communities. Since positive attitudes keep parents and community members talking in their minority language, the children get what they need to keep learning it – the rich input and ample opportunities to use it.


Lambert, W. E. (1975). Culture and language as factors in learning and education. In A. Wolfgang (Ed.), Education of immigrant students: Issues and answers (pp. 55–83). Toronto: Ontario Institute for Studies in Education.

For more information:

Crystal, D. (2010). Language death. Cambridge: Cambridge University Press.

Pearson, B. Z. (2008). Raising a bilingual child: A step-by-step guide for parents. New York: Random House.


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