How Kids Learn Language · Language-Learning

Does hearing two languages interfere with a child’s language development?

Growing up in a diverse community with many bilingual and trilingual friends, it never occurred to me that people might see bilingualism as a threat to children’s language development. In fact, in many parts of the world, people grow up fluent in two or more languages (though usually these are oral and not literary). As I was reading the books, A Parents’ and Teachers’ Guide to Bilingualism and An Introduction to Bilingual Development, I noticed that both authors, Dr. Colin Baker and Dr. Annick De Houwer, mention that one of the questions they receive most frequently from parents is whether bilingualism is bad for children. So this seems to be a common concern the world over.

The general consensus among experts is that hearing more than one language growing up does not interfere with a child’s language development. In other words, it will not “mess up” their brains or confuse them cognitively. Actual language disorders are not caused by bilingual environments. Below is a synthesis of arguments made in the books I read as well as information from a former ESL teacher and current speech language pathologist in Boston.

This post discusses whether bilingualism affects language development and language disorders and thus pertains to younger children (0-6yrs old). I will write a separate post on whether bilingualism/trilingualism affects one’s ability to speak one’s languages fluently.

Will hearing more than one language interfere with the child’s language development?

“Language development” is the process by which a child acquires a language. In other words, it is how a child goes from knowing no language to speaking and understanding a language. Milestones in language development include: babbling, starting to utter single words, moving on to saying two words, constructing longer sentences, and telling short stories.

Some parents wonder if hearing two languages may affect a child’s ability to acquire language. Experts say there is little effect, if at all. Baker writes that initially bilingual children will tend to know fewer words in each language than a monolingual child, but know more words combined. There may also be times when a bilingual child seems to be slightly behind a monolingual in learning a language. Baker notes, however, that “this lag is usually temporary. With sufficient exposure and practice, the bilingual child will go through the same language development stages as the monolingual child” (Baker 2014, 96).

De Houwer writes that children’s rates of language development vary amongst monolinguals and bilinguals and there is little if any difference in the rates of language development between monolingual and bilingual children. In the following passage, BFLA stands for Bilingual First Language Acquisition and MFLA stands for Monolingual First Language Acquisition. In the BFLA situation, a child hears two languages from birth (or even before!), and both become their first languages. In the MFLA situation, a child is exposed to one language.

“There is no research evidence showing that as a group BFLA children develop language slower than MFLA children. Instead, the combined evidence shows similar ranges of variation, with some BFLA children developing faster than some MFLA children, some MFLA children developing faster than some BFLA children, some BFLA children developing faster than other BFLA children, and some MFLA children developing faster than other MFLA children” (De Houwer 2009, 6).

So in other words, we don’t need to worry about bilingual children not being able to learn languages normally. There is no evidence that bilingual children develop language slower than monolingual children. And even if there is a lag, it is temporary and will not impact the child’s ability to progress through normal stages of language development.

So if a child in a bilingual environment does have issues with language development, what are the causes of these problems?

First let’s look at what these issues are. “Examples of symptoms of language disorders are: great difficulty in producing certain sounds; a considerable lack of understanding (or use) of familiar words; great difficulty in remembering new words despite a great deal of exposure to them; and great difficulty in expressing needs and wants without use of gestures” (Baker 2014, 109). Another language problem, one that is extremely rare, is underdevelopment of both languages, which Baker defines as when “a child is unable to cope in the curriculum in the school in either language” (Baker 2014, 85).

If a child is displaying such symptoms, it is most likely not caused by bilingual input. BFLA children do not experience more language disorders on average than MFLA children. It is more likely that a child with language disorders has a hearing problem or an undiagnosed neurological or psychological problem. And “in approximately two-thirds of all cases, the precise reason for language delay is not known” (Baker 2014, 110). Therefore, the primary cause of a language disorder is unlikely to be bilingualism.


But if a child has language problems or other disabilities, wouldn’t switching to only one language make it easier for the child to learn?

This is the advice that well-meaning practitioners and educators often give: drop one language and the child’s language problems will resolve. This is misguided, because there is no valid research that links bilingualism to language disorders or other disabilities. There is however research that shows that hearing, neurological and psychological problems lead to language disorders. So by blaming bilingual input, such practitioners actually prevent themselves from diagnosing the true cause of the problem, e.g. deafness (De Houwer 2009, 6; Baker 2014, 119). This is dangerous for the child, and a reminder that when we consult practitioners, we must make sure they have experience treating bilingual children!

But let’s say the child does have a disorder. Wouldn’t it make sense to get rid of one language? Perhaps for parents who are equally fluent in both languages. When parents can provide rich language models in both languages, switching to speaking only one language may ease the child’s disorder. In cases of language delay, there are “situations where maximal experience in one language is preferable. For example, where one language of a child is more secure and better developed than another, it may be sensible to concentrate on developing the stronger language.” And when the child is cognitively challenged, “ensuring a solid foundation in one language first is important” (Baker 2014, 111). However, it must be emphasized that these problems are not caused by bilingualism, and thus are unlikely to be solved by shifting to monolingual input alone. Baker cautions that such a shift in language usage must be a part of a “package” of solutions.

Further, more often than not, parents are not equally fluent in both languages. And more often than not, educators and practitioners will tell them to drop the language they are more comfortable in and speak only the dominant language (e.g. English) to their children. The problem with this advice is that it is based on the assumption that different languages function separately in the child’s brain and must therefore be a greater burden to the child. In reality, there are underlying principles to language acquisition, so strengthening a child’s foundation in one helps them learn another. We might analogize this to the study of foreign languages. Knowing what the word “apple” means in English will help you learn how to say it in French or Chinese, because you already understand the word “apple” and don’t have to figure it out (“Does apple refer to fruits in general? Only red fruits? round fruits with a stem?” etc). Knowing how to make counterfactual conditional statements (e.g. “If you had told me that was yours, I wouldn’t have eaten it”) helps us make these statements in other languages.

Left: How bilingualism is perceived to work. (L1 = language 1, L2 = language 2). Right: How bilingualism actually work (Source: New Zealand Ministry of Education)

In children, the cognitive skills that come with knowing one language well helps them acquire a second language as well. Therefore, it does not make sense to tell parents to drop their native language if they will have to become lesser language models as a result. My speech language pathologist friend told me that she almost never recommends parent stop speaking their native language to their child, “no matter the level of disability” for this reason. Baker also writes that “In most cases it is inappropriate to move from bilingualism to monolingualism” (Baker 2014, 111). In addition, speaking their native tongue allows the child to stay connected to their culture and enhances the parent-child relationship. If parents had been loving and caring for their child in one language, suddenly switching to another could cause the child even greater distress.

In fact, it is also possible that a child with a disability has a gift for languages, as is the case with this boy with Asperger’s syndrome who became bilingual in English and French. While this child may have had a gift for languages, his situation highlights the importance of not jumping to monolingualism as a solution to a disability.

To conclude:

  • Bilingual environments do not confuse children or interfere with their ability to acquire languages.
  • Bilingual children may have less vocabulary than monolingual children in the beginning, but on average they do not develop language abilities any slower than their monolingual counterparts.
  • Language disorders are commonly caused by hearing problems and neurological and psychological problems. Telling parents to stop speaking to their child in the language they have loved and cared for them in is almost never the right advice.

PS- I found out about these two books on bilingualism through this page: Best Books About Bilingualism for Parents.

PSS- My speech language pathologist friend also recommends the book Dual Language Development & Disorders: A Handbook on Bilingualism & Second Language Learning to learn more about language disorders in bilingual children.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s