Raising a Bilingual Baby: First Words
Sooner or later someone will tell you that two languages will slow your child down. It might be a relative. It might be a pediatrician. It's wrong, and there's now a very large study that says so plainly.
The more useful problem is quieter. Bilingual toddlers get measured with the wrong ruler, and it makes a thriving child look like a struggling one. That part you can control.
The short version. Bilingual babies babble, say first words and reach 50 words at the same ages as monolinguals. The only real risk is bookkeeping: count every word in every language, never just one.
Are bilingual babies slower to talk?
No. In 2025, researchers compared 302 bilingual children with 302 matched monolingual peers and found no significant difference in the age of babbling, the first word, the 10th word, the 50th word, the first multiword utterance, or the first three-word utterance (Muszyńska et al., Journal of Child Language).
For the first word and the 10th word, the evidence didn't just fail to find a gap. It positively confirmed there wasn't one.
Read that list again. Not one milestone moved.
How to count a bilingual baby's words
This is where good intentions go wrong. Measure only one language against a standard milestone chart and a perfectly typical bilingual toddler looks behind. So parents are told to combine the languages. Fine. But how you combine them matters more than most parents expect.
There are two methods, and they aren't interchangeable (Byers-Heinlein and colleagues wrote a whole paper on how much the choice matters, First Language, 2024):
- Total vocabulary. Every word in every language. "Dog" and "perro" count as two.
- Conceptual vocabulary. Every distinct concept. "Dog" and "perro" collapse into one.
Use total vocabulary. Core and colleagues (2013) followed 47 Spanish-English bilingual toddlers alongside 56 monolinguals at 22, 25 and 30 months:
| Counting method | What it showed |
|---|---|
| Total vocabulary | Bilingual children matched monolingual norms in size and growth, at every age |
| Conceptual vocabulary | Significantly more children looked low-average at two of the three ages, and the gap widened with age |
Count one language and you invent a delay. Count both and it disappears.
The practical version: if your daughter says 28 words in English and 24 in French, she has 52 words. Don't go looking for the overlaps and subtracting them. You'll only frighten yourself, and you'll be measuring something the researchers specifically warn against using for assessment.
Our milestone chart gives you the benchmarks to count against, and explains why even those come in two flavours.
Encouraging both languages
Vocabulary follows input. Not exposure in the passive sense of a television in the corner, but the back-and-forth kind: naming, asking, answering, repeating, singing.
- Protect the minority language. The language with fewer hours needs deliberate work, because everything else in your child's life conspires against it. Books, songs, video calls with grandparents, playdates with other families who speak it.
- Pick a pattern, any workable pattern. One parent, one language suits many families. So does one language at home and another outside, or splitting by time of day. Consistency beats any particular scheme.
- Don't correct the mixing. Respond to what your child meant, in the language you're speaking. Correction teaches children that one language is a place where they get things wrong.
- Keep it warm. Pressure makes children refuse a language. They keep the ones that feel like love.
Why writing them down matters more for you
Bilingual first words are scattered as well as fleeting. A word arrives in Portuguese at your mother's house on a Sunday. Another turns up in English at nursery on Tuesday, reported to you secondhand. No single person in your child's life hears all of them.
Keep a record. Not sentiment. Arithmetic. A total vocabulary count is the measure the research supports, and it's the one number you cannot produce from memory, because the words aren't all yours to remember.
One journal for every language they speak
Saylings was built for multilingual families. Track first words in 30+ languages, each with its own flag, colour, count and milestones, and capture each one with a photo and your child's actual voice.
Join the waitlist — launching soon on iOSCommon questions
Are bilingual babies slower to talk?
No. A 2025 study in the Journal of Child Language compared 302 bilingual toddlers with 302 monolinguals and found no significant difference in the age of babbling, the first word, the 10th word, the 50th word, or the first multiword utterance. Bilingualism does not cause language delay.
How do you count words for a bilingual baby?
Use total vocabulary: add every word in every language, counting "dog" and "perro" as two. Core and colleagues (2013) found total vocabulary matched monolingual norms, while conceptual counting, which merges translation pairs, flagged significantly more bilingual children as low-average at two of three ages.
Is it bad if my child mixes languages in one sentence?
No. Code-mixing is a normal feature of bilingual speech at every age, and fluent bilingual adults do it too. It reflects having two systems available, not confusion between them, and it isn't a sign that a child needs intervention.
Should each parent speak a different language?
One parent, one language works for many families, but it isn't the only workable pattern. What drives vocabulary is the quantity and quality of interaction a child gets in each language, not the rule used to divide them.
This article is general information for parents, not medical or speech-language advice. If you have concerns about your child's speech in any language, a bilingual speech-language pathologist or your pediatrician can help. Assessment in only one language will understate a bilingual child's ability.
Sources
- Muszyńska K, Krajewski G, Dynak A, Garmann NG, Romøren ASH, Łuniewska M, Alcock K, Katsos N, Kołak J, Simonsen HG. Bilingual children reach early language milestones at the same age as monolingual peers. Journal of Child Language. 2025;53(2):365–388. doi.org/10.1017/S0305000924000655
- Core C, Hoff E, Rumiche R, Señor M. Total and Conceptual Vocabulary in Spanish–English Bilinguals From 22 to 30 Months: Implications for Assessment. J Speech Lang Hear Res. 2013;56(5):1637–1649. Retrieved 9 July 2026. pmc.ncbi.nlm.nih.gov
- Byers-Heinlein K, Gonzalez-Barrero AM, Schott E, Killam H. Sometimes larger, sometimes smaller: Measuring vocabulary in monolingual and bilingual infants and toddlers. First Language. 2024. doi.org/10.1177/01427237231204167
- American Speech-Language-Hearing Association, Communication Milestones: 19 to 24 Months. Retrieved 9 July 2026. asha.org