pediatric-development
Raising a Bilingual Child: Speech Development and What to Expect
Bilingualism does not cause speech delays [1]. Bilingual children's total vocabulary across both languages follows typical timelines [2]. True delays affect both languages and warrant evaluation with an SLP experienced in bilingual assessment [3].
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Find care →How bilingual language development actually works
Children raised with two languages are learning two full linguistic systems simultaneously. Research consistently shows that bilingual children are not slower to reach language milestones when both languages are counted together 1Ref 1Hambly H, Wren Y, McLeod S, Roulstone S (2013).The Influence of Bilingualism on Speech Production: A Systematic Review.Systematic review finding bilingualism does not cause speech delays; bilingual children reach overall communication milestones on the same timeline as monolinguals when both languages are considered. A bilingual child may have fewer words in each individual language than a monolingual peer while having a combined vocabulary that is entirely typical 2Ref 2Bedore LM, Peña ED, García M, Cortez C (2010).Conceptual Versus Monolingual Scoring: When Does It Make a Difference?.A bilingual child's total conceptual vocabulary across both languages falls within typical range even when single-language scores individually appear reduced. Studies measuring total conceptual vocabulary — counting a word once even if the child knows it in both languages — show that bilinguals' expressive vocabularies match those of monolingual peers at the same ages. A per-language lag of roughly 21 percentile points is normal and expected; it does not signal a disorder 4Ref 4Nicoladis E, Paradis J (2023).Why bilingual development is not easy.Bilingual children show a receptive-expressive gap (understand more than they produce per language) and a 21-percentile-point per-language vocabulary lag that disappears when total cross-language vocabulary is counted.
Code-switching is normal, not a problem
Mixing words or phrases from two languages within a single sentence — called code-switching or code-mixing — is a normal feature of bilingual speech, not a sign of confusion or failure to separate the languages. Bilingual adults do it too. Children often switch between languages based on which word comes most easily in the moment, who they are talking to, or the topic. It is not something families need to try to suppress, and suppressing it can reduce a child's communicative confidence without any developmental benefit.
Milestones to think about across both languages
When tracking a bilingual child's development, it helps to think about total communication rather than single-language word counts 2Ref 2Bedore LM, Peña ED, García M, Cortez C (2010).Conceptual Versus Monolingual Scoring: When Does It Make a Difference?.A bilingual child's total conceptual vocabulary across both languages falls within typical range even when single-language scores individually appear reduced. A 24-month-old who knows 30 words in one language and 25 in another has a combined expressive vocabulary that may fall within typical range — even if neither list alone reaches common single-language benchmarks of 50 words by age 2 5Ref 5Centers for Disease Control and Prevention (2024).Learn the Signs. Act Early. — Developmental Milestones.CDC milestones framework used to track communication development in all children, including bilingual children, across ages 2 months to 5 years. Beyond vocabulary, the milestones that matter most are the same as for any child: Is the child communicating intentionally? Following simple instructions in at least one language? Combining words into short phrases? Engaging socially through pointing, eye contact, and shared attention? These social-communication milestones do not depend on which language is used.
What a true delay looks like in a bilingual child
A true speech or language delay in a bilingual child affects both languages — it is not explained by bilingualism itself 1Ref 1Hambly H, Wren Y, McLeod S, Roulstone S (2013).The Influence of Bilingualism on Speech Production: A Systematic Review.Systematic review finding bilingualism does not cause speech delays; bilingual children reach overall communication milestones on the same timeline as monolinguals when both languages are considered. Signs that warrant evaluation include: limited or no word combinations in either language by 24 months; difficulty understanding instructions in both languages; speech that is unclear to familiar caregivers in both languages; or social communication concerns such as not pointing to share interest or not responding to their name. If a child is clearly delayed in one language but not the other, that may reflect language exposure and dominance rather than a true delay — an SLP experienced with bilingual children can help sort this out 3Ref 3American Speech-Language-Hearing Association (2023).Multilingual Service Delivery in Audiology and Speech-Language Pathology (Practice Portal).ASHA guidance on assessing bilingual children, including the need for SLPs experienced with bilingual populations and assessment in both languages.
Getting a bilingual-informed evaluation
It is important to seek a speech-language pathologist who has experience evaluating bilingual children, or who can arrange assessment in both of a child's languages 3Ref 3American Speech-Language-Hearing Association (2023).Multilingual Service Delivery in Audiology and Speech-Language Pathology (Practice Portal).ASHA guidance on assessing bilingual children, including the need for SLPs experienced with bilingual populations and assessment in both languages. Standard assessments normed on monolingual English speakers can underestimate a bilingual child's abilities and lead to misidentification of delay when none exists. An SLP should ask about each language's role in the child's life — which language is spoken at home, at childcare, with extended family — and interpret results with that context in mind. Parents should advocate for this if it is not offered. ASHA's practice portal on multilingual service delivery provides guidance on best practices 3Ref 3American Speech-Language-Hearing Association (2023).Multilingual Service Delivery in Audiology and Speech-Language Pathology (Practice Portal).ASHA guidance on assessing bilingual children, including the need for SLPs experienced with bilingual populations and assessment in both languages.
Common questions
Should I only speak one language to my child to avoid confusing them?
There is no evidence that speaking two languages confuses children or causes delays [1]. Most speech-language pathologists advise parents to speak to their children in the language they are most fluent and comfortable in — authentic, rich input in any language supports development better than strained or limited exposure to a language a parent does not know well.
My child's daycare only speaks English. Will my home language fall behind?
Possibly. Children tend to develop stronger language skills in the language they hear most. If the home language gets less daily exposure, it may become the weaker language over time [4]. Maintaining rich exposure at home — reading, storytelling, talking together — can help support both languages.
My bilingual child is behind in both languages. What should I do?
Being behind in both languages — not just the less-dominant one — is the clearest signal that something other than bilingualism may be at play [1]. This warrants a speech-language evaluation, ideally with a clinician experienced in bilingual development [3].
At what age should a bilingual child be using both languages clearly?
The timeline for clarity in each language roughly parallels typical monolingual development in that language, adjusted for exposure [5]. A child who hears Language A primarily at home and Language B at school may reach clarity benchmarks in each language at somewhat different ages. This is normal.
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Lena Park, PNP — Pediatric NP
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Find care →When to get care right away
- —No words in either language by 16 months
- —No two-word combinations in either language by 24 months
- —A child who does not respond to their name or to simple instructions in their dominant language by 18 months
- —Loss of previously acquired words in either language
This article is general health education and does not constitute a diagnosis or individualized guidance. A speech-language pathologist experienced with bilingual children can assess a specific child's communication development.
References
- 1.Hambly H, Wren Y, McLeod S, Roulstone S (2013). The Influence of Bilingualism on Speech Production: A Systematic Review. International Journal of Language & Communication Disorders. doi:10.1111/j.1460-6984.2012.00178.x ✓Systematic review finding bilingualism does not cause speech delays; bilingual children reach overall communication milestones on the same timeline as monolinguals when both languages are considered
- 2.Bedore LM, Peña ED, García M, Cortez C (2010). Conceptual Versus Monolingual Scoring: When Does It Make a Difference?. Language, Speech, and Hearing Services in Schools. doi:10.1044/0161-1461(2009/08-0040) ✓A bilingual child's total conceptual vocabulary across both languages falls within typical range even when single-language scores individually appear reduced
- 3.American Speech-Language-Hearing Association (2023). Multilingual Service Delivery in Audiology and Speech-Language Pathology (Practice Portal). ASHA Practice Portal. link ✓ASHA guidance on assessing bilingual children, including the need for SLPs experienced with bilingual populations and assessment in both languages
- 4.Nicoladis E, Paradis J (2023). Why bilingual development is not easy. Frontiers in Psychology / PMC. link ✓Bilingual children show a receptive-expressive gap (understand more than they produce per language) and a 21-percentile-point per-language vocabulary lag that disappears when total cross-language vocabulary is counted
- 5.Centers for Disease Control and Prevention (2024). Learn the Signs. Act Early. — Developmental Milestones. cdc.gov. link ✓CDC milestones framework used to track communication development in all children, including bilingual children, across ages 2 months to 5 years
5 sources, numbered by first appearance. General health information, not medical advice — synthetic demonstration content.