Bringing Up (Bilingual) Bébé
There’s a lot of, sometimes confusing, information out there about language development, especially when it comes to young bilingual language learners.

Let’s go through a couple common questions and terms that parents often bring up when asking about what’s best for their children who are learning multiple languages.
We’ll dive into what being bilingual actually means, the different types, and MOST of all, how exposing your child to multiple languages will NOT cause or worsen a language delay or disorder.
What does being Bilingual mean?
Let’s bust one misconception right away:
Being bilingual does not mean someone is equally proficient in both languages.
In fact, most multilingual learners have stronger skills in one language over the other and their preference or proficiency in each can change over time.
Types of Bilingual Language Learners
Not only do bilingual/multilingual learners have different proficiency levels in each language, but there are also different types of bilingual learners!
The distinction between sequential and simultaneous bilingual learners all depends on when they were first exposed to each language.
Sequential: learn a first language before age 3 and then another (second) language sometime after. For example, this would describe a child who heard and spoke Portuguese at home with their parents and other language partners (grandparents, family friends), and had their first main exposure to English when they went to preschool at age 4.
Simultaneous: learn two or more languages at the same time, with both languages being introduced before the age of 3. For example, this would describe a child who has heard and spoken a mix of Portuguese and English with their parents and other language partners (family friends, nanny, etc.) since birth.
Scapegoat of Bilingualism
Another big misconception to bust:
Learning 2 or more languages at a young age does NOT cause a language delay!
Multiple studies have shown that language development milestones of monolingual and bilingual children are the same (ASHA, 2019; Kohnert, 2013; Paradis, Genesee, & Cargo, 2011).
This means that children start babbling, saying their first words, and creating sentences around the same time -- whether they are monolingual or bilingual. Rates of language disorders among both groups are roughly the same as well.
If that doesn’t convince you, listen to the U.S. department of health and human services and the US department of education! In 2017, they stated “there is no scientific research that suggests that learning multiple languages – or being bilingual – can lead to a developmental delay for children.”
Bilingual and multilingual kids can have delays, disorders, and differences, too. But don’t let their multiple languages be a scapegoat for their diagnoses!
Frequently Asked Questions
Should I still use both language if my child is delayed, is neurodivergent and/or has a disability?
Research shows that exposure to two languages from birth does not make a language disorder more severe. A language disorder doesn’t mean a child can’t learn two languages (Paradis & Kirova, 2014).
Don’t be afraid of speaking your home language with your child even if they have a delay, disability, and/or neurodivergent profile – research clearly shows that exposure to two languages does no harm.
Won’t my child get confused with having two languages?
Nope! We don’t actually have this big system where all the languages we learn are dumped and mixed together into one brain pot. Instead, bilingual kids actually develop separate systems for each language that sometimes interact (Dual Language Systems Hypothesis). This leads kids to eventually have separate vocabulary, grammar, etc. systems for each language to pull from. However, these systems do communicate with each other. This can lead to code-mixing, where bilingual people use some words from both languages in the same sentence. This doesn’t mean they’re confusing the two languages while speaking. Instead, code-mixing can occur for a variety of reasons. Sometimes if a child doesn’t know or cannot quickly retrieve a word in one of their languages, they may borrow the word from their other language. Just like a monolingual child may use ”dog” to refer to any four legged animal, a bilingual child may use the Spanish word for “dog” (“perro”) when speaking in English. They use their emerging vocabulary system efficiently, using vocabulary they DO know to make up for what they DON’T know (yet) (Lanza, 2004 as cited in Byers-Heinlein & Lew-Williams, 2013). Code mixing can be an expected and important part of a bilingual community, and is often the norm in many Spanish-English communities in the U.S (Byers-Heinlein & Lew-Williams, 2013). Therefore, children who say a sentence with a mix of Spanish and English words may just be imitating the language styles they’ve heard others in their community use. As further evidence for children not getting confused, children as young as two show the ability to change their language based on their communication partner (Genesee, Boivin, & Nicoladis, 1996 as cited in Byers-Heinlein & Lew-Williams, 2013). This suggests that even very early in development, children have some knowledge that they are learning and using two separate languages, and can switch between them intentionally. BOTTOM LINE — there is no evidence to suggest that your child will be confused by learning multiple languages at a young age.
Will my bilingual child’s development look different AT ALL?
Maybe a little bit. But not in a bad way! Vocabulary acquisition may appear different early on. It may seem like bilingual kids have less vocabulary than monolingual kids. However, they actually have the same vocabulary breadth, but their words are spread across 2 languages. This means that if you add their vocabulary knowledge between their two (or more) languages, they know about the same amount of words as their monolingual peers (Marchman et al, 2010; Byers-Heinlein & Lew-Williams, 2013).
Should I always speak to my child in the language they’ll use at school?
Not necessarily. What matters most for your child is not that they’re using their school based language at home, but that they’re receiving overall high quality language input.
Caregivers using English at home is not a strong predictor of English language proficiency for bilingual or multilingual children later on (Paradis & Kirova, 2014). This is likely because many bilingual parents are not fluent English speakers themselves. In an effort to expose their child to more English at home, they use less complex grammar and vocabulary, ultimately exposing their child to less complex language overall.
Instead, it's the overall richness of language use and quality of parent-child interactions that impact language development. Speaking to your child in the language you are the most proficient and comfortable in will naturally give them exposure to more complex language.
Instead of worrying about whether they’re getting enough practice with their school-based language at home, focus on providing positive, language rich interactions, like book reading or child-led play, in whatever language you feel most comfortable speaking (Paul, Norbury, & Gosse, 2018).
What should you look for in an SLP if your child is bilingual or multilingual?
Of course, we always support more bilingual and multilingual SLPs in the field. Having someone who speaks all of a child’s languages may make interactions with caregivers and cultural exchanges easier. However, there are not as many bilingual and multilingual SLPs in the U.S. as we would like and getting consistent access to one can be difficult. More research is needed, but the good news is that recent studies suggest that therapeutic gains in one language often transfer into a client’s other languages (Danahy et al, 2015; Gildersleeve-Neumann & Goldstein, 2015). Similar to how we explained that modeling complex language in one language will aid in your child’s overall language development, a child’s overall language system will benefit from language therapy, even if it’s just in one of the child’s languages. When looking for an SLP for your bilingual or multilingual child, it is important to find someone who:
Knows that bilingualism does not cause or lead to language delays or disorders
Gets interpreters for assessments and parent discussions, as needed. This is particularly important when taking initial assessments to account for your child’s development in both languages. This will assure that a child is truly experiencing a language delay, disorder, or difference, rather than just showing stronger skills in one language over another.
Recognizes or is willing to learn the possible influences of your child's languages on each other, their dialect, and grammatical development. This could be a post on its own, but dialects, such as one influenced by someone’s other languages, are a difference not a disorder.
Take Aways:
Remember that:
Bilingual individuals are not normally equally proficient in both languages
There is a difference between Sequential vs Simultaneous dual language learners
Bilingualism does not cause delays or disorders, and will not exacerbate your child’s delay or disorder either
Interact with your child in whichever language you're most comfortable with
If you suspect that your bilingual or multilingual child has a language delay, find an SLP educated in bilingualism topics
References:
Byers-Heinlein, K., & Lew-Williams, C. (2013). Bilingualism in the Early Years: What the Science Says. LEARNing landscapes, 7(1), 95–112.
Danahy Ebert, K., Kohnert, K., Giang Pham, Rentmeester Disher, J., & Payesteh, B. (2014). Three Treatments for Bilingual Children With Primary Language Impairment: Examining Cross-Linguistic and Cross-Domain Effects. Journal of Speech, Language & Hearing Research, 57(1), 172–186. https://doi-org.ezproxy.bu.edu/10.1044/1092-4388(2013/12-0388)
Genesee, F. (2010). Dual language development in preschool children. Young English language learners: Current research and emerging directions for practice and policy, 59-79.
Gildersleeve-Neumann, C., & Goldstein, B. A. (2015). Cross-linguistic generalization in the treatment of two sequential Spanish-English bilingual children with speech sound disorders. International Journal of Speech-Language Pathology, 17(1), 26–40. https://doi-org.ezproxy.bu.edu/10.3109/17549507.2014.898093
Kohnert, K. (2013). Language Disorders in Bilingual Children and Adults (2nd ed.). San Diego, CA: Plural Publishing Inc.
Paradis, J., Genesee, F., & Crago, M.B. (2011). Dual language development and disorders: A handbook on bilingualism and second language learning (2nd ed.). Baltimore, MD: Brookes
Paradis, J., & Kirova, A. (2014). English second-language learners in preschool. International Journal of Behavioral Development, 38, 342 - 349.
Paul, R., Norbury, C., & Gosse, C. (2018). Language disorders from infancy through adolescence: Listening, speaking, reading, writing, and Communicating (5th ed.). Elsevier.
Tenés, L. S., Weiner-Bühler, J. C., Volpin, L., Grob, A., Skoruppa, K., & Segerer, R. K. (2023). Language proficiency predictors of code-switching behavior in dual-language-learning children. Bilingualism: Language and Cognition, 1-17.