Typical Vocabulary for an 18-Month-Old Child
An 18-month-old child typically speaks 10-15 words, according to the American Academy of Pediatrics 1.
Expected Language Milestones at 18 Months
- By 18 months, children should have a productive vocabulary of 10-15 words that they can say spontaneously, not just imitate 1.
- Children at this age are on the cusp of a major language expansion—by 19-24 months, they typically begin combining two words together (like "Mommy shoe") and reach approximately 50 words 1.
- Comprehension vocabulary is substantially larger than expressive vocabulary at this age; children understand far more words than they can produce 2.
Important Context About the 18-Month Assessment
The evidence reveals important nuances about assessing vocabulary at exactly 18 months:
- Research shows that approximately 10% of 18-month-olds produce fewer than 8 words, and about one-third of these children catch up to fairly normal performance within just a few months 3.
- This suggests that 18 months may be slightly early for definitive concern, as some children are simply on the later end of normal development and will rapidly accelerate 3.
- However, children who remain below 10-15 words at 18 months warrant close monitoring, as this represents the lower boundary of typical development 1, 3.
When to Be Concerned
If an 18-month-old has fewer than 8-10 words, follow-up assessment within 3-6 months is recommended rather than immediate intervention, given the high rate of spontaneous catch-up 3.
Key red flags that require immediate evaluation include:
- Regression in previously acquired language skills 1.
- Poor social engagement or limited eye contact accompanying the language delay 1.
- Inability to follow simple one-step commands by 18 months 1.
- Lack of communicative intent (not attempting to communicate through gestures, vocalizations, or other means) 4.
Supporting Language Development at This Age
Parents should implement evidence-based strategies:
- Respond immediately to all vocalizations and communication attempts, even if just babbling, and expand on what the child expressed 1.
- Use the expansion technique: if the child says "dog," respond with "Yes, that's a big brown dog running!" 1.
- Read books together daily and provide a language-rich environment with diverse vocabulary exposure 1.
- Practice turn-taking in "conversations", allowing adequate pause time for the child to process and respond 1.