We live in Chicago, IL (US). Our son Mat
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We live in Chicago, IL (US). Our son Mateo is exactly 18 months old today (born full-term at 39 weeks).
We speak both English and Spanish at home. ight now, he only speaks about 3 consistent words: "mama", "dada", and "agua".
However, his non-verbal communication is very active: he points to show us things, waves hello/goodbye, claps when excited, and follows 1-step directions in both languages (like "bring me the ball" / "ven aquí").
My in-laws are pressuring us to drop Spanish completely, claiming that learning two languages is "confusing his brain" and causing a speech delay. His 18-month well-child pediatrician checkup is next Tuesday.
1. What does the CDC 18-month milestone checklist actually expect (what 75%+ of children do) for language and communication?
2. Does a bilingual home cause language delays, and should parents ever drop their home language?
3. How should we write down our observations for next Tuesday's visit to ask our pediatrician for a formal developmental screening?
Answer
I'll pull his profile, run the age script, and open the matching references in parallel.
Now let me open the 18-month card itself.
At 18 months on the CDC card, the language row most 75%+ children hit is "tries to say three or more words besides 'mama' or 'dada'" and "follows one-step directions without any gestures, like giving you the toy when you say, 'Give it to me.'" Mateo is right on the second one (in both languages) and one short on the first: across English and Spanish he has 3 words, only 1 of them ("agua") is outside mama/dada.
Source: https://www.cdc.gov/act-early/milestones/18-months.html
That gap is real but small, and the bilingual home is not what's causing it. The in-laws' instinct — drop Spanish — would be the wrong move.
**1. Does bilingual cause delay? No.**
- Learning two languages does not confuse a child's brain or cause speech delays. The American Speech-Language-Hearing Association is direct on this.
- Count words, combinations and gestures across every language he hears. A real problem shows up in all of them, not just one.
- Keep using the language(s) you're most comfortable speaking at home. Dropping a home language is not a treatment.
- Source: https://www.asha.org/public/speech/development/learning-more-than-one-language/
- Source: https://www.nhs.uk/start4life/chatplayread
Mateo's pointing, waving, clapping and 1-step following — in both English and Spanish — are the gestures row of the 18-month card. That row is filled, in every language he uses.
**2. The CDC's four prompts for the visit, with what to bring Tuesday:**
| CDC prompt | What to write down (today, 2026-09-16) |
| --- | --- |
| What do you do together? What does he like? | 2–3 everyday moments — bath books, kitchen cabinet, "agua" at the park |
| Anything he does or doesn't do that concerns you? | "18 months, 3 consistent words total across English+Spanish: mama, dada, agua. Below the 75% row for words besides mama/dada." |
| Has he lost any skills? | (date + yes/no, with one example) |
| Born prematurely / special healthcare needs? | Born at 39 weeks. No. |
Bring, dated:
- **Hearing:** "Turns to name in a quiet room — yes / no" (the one item that would change the reading fastest).
- **Language:** the 3 words, both languages; any word-attempts you can write down phonetically ("agu" for water, etc.).
- **Gestures:** points to show, waves, claps, brings things to you — all dated today.
- **Both sides of the body:** does he reach, point and hold things with both hands?
**3. What to ask for on Tuesday:**
| When | What to do |
| --- | --- |
| Today | Write the row above. Don't drop Spanish. |
| Tuesday, 2026-09-22 | At the 18-month well-child visit, ask the pediatrician for a **formal developmental screening** (the US schedule has general screening at 9, 18 and 30 months — this is the 18-month slot, and autism-specific screening is also done at 18 months). Bring the dated notes. |
You're not asking the pediatrician to label anything — you're asking for the validated questionnaire (often the ASQ-3, with the M-CHAT-/F for the autism side). Screening is a parent's right at this visit; you don't need a referral to ask.
**One thing that would change how I read this:** has he ever had more words, or any of the small skills above (pointing, waving, clapping), that he did for a while and then stopped?