Does Raising a Bilingual Child Cause Speech Delay? The Facts

What does the research actually show?

Research does not bear out the common worry that two languages overload a young child and slow speech. Bilingual children reach key language milestones — first words, word combinations, growing sentences — within the same general range as children learning a single language. Milestone guides apply across the board: they describe what most children do by a given age regardless of how many languages they hear 1Ref 1Zubler JM, Wiggins LD, Macias MM, Whitaker TM, Shaw JS, Squires JK, Pajek JA, Wolf RB, Slaughter KS, Broughton AS, Gerndt KL, Mlodoch BJ, Lipkin PH (2022).Evidence-Informed Milestones for Developmental Surveillance Tools.Evidence-informed milestones describe what most children do by a given age and apply regardless of how many languages a child hears.. Learning two languages is a normal, achievable task for a young brain.

What's normal for bilingual kids?

Some patterns look different from monolingual development but are completely typical:

• Fewer words per language, similar total. Counting both languages together, bilingual children's vocabularies are comparable to peers'. Counting only one language can make it look smaller than it is.
• Mixing languages (code-switching). Using words from both languages in one sentence is a sign of flexible skill, not confusion.
• A 'silent period.' A child newly exposed to a second language (for example, starting daycare in a new language) may listen quietly for a while before speaking it.
• One stronger language. It is normal for the language a child hears most to be ahead of the other, and for that to shift over time.

How do you count words fairly?

When you wonder whether your bilingual child is 'behind,' add up what they can say and understand across both languages, not just one. A child who says ten words in Spanish and five in English knows fifteen words — a fair comparison to a monolingual child's fifteen. Likewise, look at understanding, gesturing, and pointing in either language. CDC milestone checklists are a useful reference for the kinds of skills to look for at each age 2Ref 2Centers for Disease Control and Prevention (CDC) (2024).CDC's Developmental Milestones — Learn the Signs. Act Early..CDC milestone checklists provide age-based skills to look for and guide parents to act early when they are missed., applied across your child's full linguistic world.

When is a delay real, and what should you do?

Because bilingualism does not cause delay, never use 'it's just the two languages' to wave off a genuine concern. A true language delay shows up in both languages, not just one. Watch for:

• Very few words or no word combinations across both languages by the usual ages.
• Losing words or skills in either language.
• Trouble understanding simple requests in the home language.
• Little pointing, eye contact, or shared attention.

The AAP recommends developmental surveillance at every well-child visit and standardized screening at key ages 3Ref 3Lipkin PH, Macias MM; AAP Council on Children with Disabilities, Section on Developmental and Behavioral Pediatrics (2020).Promoting Optimal Development: Identifying Infants and Young Children With Developmental Disorders Through Developmental Surveillance and Screening.AAP recommends developmental surveillance at every visit plus standardized screening at key ages, the right moment to assess a bilingual child's language. — the right moment to raise a bilingual child's language, too.

When your bilingual child's speech needs a clinician

A pediatrician and a bilingual or interpreter-supported speech-language pathologist add value precisely because bilingual development can be misread. They can assess language across both languages with validated tools, so a child is not wrongly labeled delayed (or wrongly reassured) based on one language alone 3Ref 3Lipkin PH, Macias MM; AAP Council on Children with Disabilities, Section on Developmental and Behavioral Pediatrics (2020).Promoting Optimal Development: Identifying Infants and Young Children With Developmental Disorders Through Developmental Surveillance and Screening.AAP recommends developmental surveillance at every visit plus standardized screening at key ages, the right moment to assess a bilingual child's language.. They can rule out medical causes such as hearing loss that affect every language a child is learning. When a real delay is confirmed, they deliver evidence-based, parent-coached intervention and — importantly — will tell you to keep both languages rather than drop one, because dropping the home language does not speed things up and can cost a child connection with family. They can also coordinate with bilingual childcare or preschool. The clear message: you do not need to give up your home language to support your child's speech.