Will Being Bilingual Delay Speech? (An SLP Answers)
By Lindsey Carleton, MA, CCC-SLP
No. Being bilingual does not delay speech. That has been the consistent finding of speech-language research for at least three decades, supported by ASHA, the CDC, and every major position statement on bilingualism in child development. And yet I still hear this myth in pediatrician offices every week.
Here’s what the research actually shows, why the myth persists, and the few times when a speech delay is real (and what to do).
The short answer, clearly
Bilingual children hit the same speech-and-language milestones as monolingual children, within the same age ranges. About 5–10% of all children have a speech or language delay — that rate is identical in bilingual and monolingual populations.
What changes in bilingual children is how you measure progress, not the underlying ability.
Why the myth keeps spreading
A few reasons this won’t die:
Measurement error
A bilingual 2-year-old might know 40 words in English and 35 in Spanish — a total of 75 unique words. A monolingual 2-year-old might know 70 in English alone. If you measure only English, the bilingual child appears behind. They aren’t.
Older professionals trained before the consensus shifted
Some pediatricians and SLPs received their training before the bilingualism research consolidated in the 2000s and 2010s. The advice “drop one language to help speech” reflects outdated thinking.
Anecdote bias
A family knows one bilingual child who was a late talker; they conclude bilingualism delayed speech. They didn’t know the same child would have been a late talker monolingually too. Roughly 1 in 7 toddlers (about 13–15%) are late talkers regardless of language exposure (ASHA, Late Language Emergence).
Code-switching mistaken for confusion
A bilingual toddler saying “Quiero un cookie” is doing sophisticated linguistic work, not failing. See why your bilingual child mixes English and Spanish.
What ASHA and the research actually say
The American Speech-Language-Hearing Association (ASHA) explicitly states that bilingualism does not cause or worsen language delays. From their official position: bilingual children should be evaluated in both languages, and dropping one language is not a treatment for speech delay.
Major bilingualism researchers (including frequently-cited work by Dr. Erika Hoff, Dr. Ellen Bialystok, Dr. Barbara Pearson, and others) have shown:
- Vocabulary across both languages combined matches monolingual peers
- Phonological development follows the same timeline
- Grammar acquisition in bilingual kids is on track for both languages
- Cognitive benefits of bilingualism (e.g., executive function) appear early
See our deeper take in bilingual children myths debunked and the bilingual brain.
How to count bilingual vocabulary
Here’s the trick most non-bilingual SLPs miss. To measure a bilingual toddler’s vocabulary fairly, count unique concepts across both languages — not just one language.
Example for a 24-month-old:
| Word | English | Spanish |
|---|---|---|
| dog | yes | perro (no) |
| cat | yes | gato (yes) |
| more | yes | más (yes) |
| water | no | agua (yes) |
| ball | yes | pelota (no) |
That child’s unique-concept count is 5, not 3 (English alone). Bilingual count is the appropriate metric. See more in bilingual toddler vocabulary counting both languages.
What real speech delays look like in bilingual kids
A delay is real (and worth evaluating) when, across both languages combined, the child shows:
- Under 50 unique words by 24 months
- Not combining two words by 24–30 months
- Unintelligible to family more than 50% of the time at age 3+
- No babbling by 12 months
- Loss of previously acquired words at any age
If any of these are happening, get an evaluation. From a bilingual SLP ideally.
Worried your child has a delay? Don’t blame Spanish first. Start with an evaluation in both languages. And keep using the 12-month curriculum — structured bilingual input supports, not harms, kids with delays.
The “drop one language” advice is wrong
If a pediatrician or SLP tells you to drop Spanish (or any second language) to “help” your child’s speech, get a second opinion. From ASHA’s perspective, this advice:
- Has no research support
- Cuts off the child from family and culture
- Doesn’t actually improve speech outcomes
- Often makes things worse by reducing total language input
The right move is the opposite: maintain bilingual input and get evaluated in both languages by someone qualified.
See our full discussion in should you stop teaching Spanish if your child has a speech delay and bilingual development for children with speech and language differences.
What “silent period” is (and isn’t)
Some bilingual toddlers go through a silent period where they understand both languages but speak less than expected for a few months. This is not a delay — it’s a normal phase as the child sorts the two systems. Usually resolves in 1–3 months.
The silent period is real. It’s also commonly misdiagnosed as a delay. See why your bilingual toddler isn’t talking back.
Bilingual late talkers: what to do
Roughly 1 in 7 toddlers (about 13–15%) are “late talkers” — slower to start speaking but typically catch up by age 3 or 4. Bilingual late talkers are no different.
If your bilingual 2-year-old has fewer than 50 total words (across both languages combined), it’s reasonable to:
- Schedule an evaluation with a bilingual SLP if available
- Continue both languages — do NOT drop one
- Maximize interactive, face-to-face input (reading, singing, talking)
- Reduce screen time temporarily
- Re-evaluate in 6 months
Most late talkers catch up fully. Those who don’t benefit from early intervention — in both languages.
Specific bilingual myths to push back on
A few statements you might hear that are wrong:
| Myth | Reality |
|---|---|
| ”Pick one language until age 5” | No research support; harmful to identity |
| ”Bilingualism causes stuttering” | False — see bilingual stuttering and disfluencies |
| ”Bilingual kids talk later” | Some do, but the rate matches monolinguals |
| ”Mixing languages = confusion” | Mixing = sophisticated processing |
| ”Wait until English is solid” | Bilingual exposure should be early and continuous |
The cognitive upside
While we’re here, the positive research is worth knowing. Bilingual children show:
- Enhanced executive function (focus, task-switching)
- Stronger metalinguistic awareness (understanding that language is a system)
- Better social cognition (perspective-taking)
- Cognitive flexibility into adulthood
- Often higher academic outcomes in late elementary and beyond
The point isn’t that bilingualism makes kids “smarter.” It’s that the supposed cost (speech delay) isn’t real, and there are documented benefits.
What to say to a doubting family member
A short script:
“Research from ASHA and decades of speech-language studies show bilingualism doesn’t delay speech. My pediatrician is on board, and we measure her vocabulary across both languages combined. She’s right on track.”
That’s it. Don’t argue science with people who don’t read science. Just hold your line.
Where to go for more
If you want the deeper version:
- Bilingual speech development overview
- Speech delay vs bilingual difference
- ASHA milestone checklists at our resources page
- CDC milestone tracker also linked at resources
For a structured bilingual program that supports rather than competes with speech development, the Palabra Garden 12-month curriculum is built by an SLP specifically with this research in mind. The free printable is a no-cost starting point.
Frequently asked questions
Is it true bilingual kids talk later?
It’s a myth in the way it’s usually stated. Bilingual kids hit the same milestones, in the same age ranges, as monolingual kids. Roughly 1 in 7 toddlers of any background (about 13–15%) are “late talkers” — that ratio is identical in bilingual and monolingual populations.
My pediatrician told me to stop Spanish. What now?
Get a second opinion, ideally from a bilingual SLP. This advice contradicts ASHA’s official position. You can also share ASHA’s bilingualism statement with your pediatrician — many will reconsider when they see it in writing.
How do I know if my bilingual child has a real delay?
Count vocabulary across both languages combined. A child with fewer than 50 unique words at 24 months (across both languages) warrants evaluation. A child with 50+ words split unevenly across languages is typically fine.
Does bilingualism affect stuttering?
No. Bilingualism does not cause stuttering. The research on whether prevalence differs is mixed — but a child’s underlying tendency to stutter exists regardless of how many languages they hear. Brief disfluencies are normal in bilingual toddlers — see bilingual stuttering and disfluencies.
Is there an age limit for starting Spanish?
No upper limit, but earlier is easier. Early childhood is the easiest window for picking up a second language — it comes with far less deliberate effort than it tends to later on. See when should I start teaching my child Spanish.
What about kids with autism or other diagnoses?
Bilingualism is also safe and beneficial for children with autism, Down syndrome, and other neurodevelopmental conditions. See bilingual development for children with speech and language differences for the research.
