Like many parents, I kept track of my son’s earliest words for his scrapbook. But after reading How Babies Talk: The Magic and Mystery of Language in the First Three Years of Life, I became fascinated by language development and how toddlers acquire speech.
The book introduced the concept of the “language explosion”—the moment when a toddler goes from learning one word a day (or every few days) to suddenly picking up as many as 10 words daily. This rapid expansion typically happens around 18 months or after a child has around 100 words.
Since my son was 18 months when I read the book, I figured—why not track his language burst and see how it happens?
When Did My Son’s Language Explosion Happen?
Not quite when I expected!
Many toddlers hit their language explosion at 18 months or around 100 words, but my son didn’t reach his until he had nearly 200 words—shortly after his second birthday. Just goes to show that every child is different!
The First 50 Words: Spoken & Signed (12-18 Months)
I initially included sign language in my early tracking since my son used spoken words and signs. This combination was incredibly useful for communication.
My son’s first five spoken words were “Mom,” “Remy” (our cat), “plane,” “spin,” and “swing.” These were followed by four signs: “more,” “milk,” “fan,” and “all done.”
Why “fan”? I was taking Lane Rebelo’s Tiny Signs course (now called The Baby Sign Roadmap). Lane Rebelo has also written a number of books—they’re fantastic resources. Lane suggested starting with two signs that were functional and two that were fun. Like many toddlers, my son was fascinated by ceiling fans.
I unfortunately didn’t continue tracking his sign language, but he did learn and use other signs such as “spin” and “ball.”
Speech Development from 18 to 26 Months
At 18 months, our pediatrician said she wouldn’t be concerned about a speech delay unless a child had fewer than 20 words. My son had 60. From 18 to 24 months, he was learning around 20 new words (or signs) per month.
Even though my son could repeat words when asked, he wasn’t repeating words he overheard—whether from conversations, music, or television. That changed around age 2, when we saw a big shift.
At 25 months, his language explosion truly began.
- He started repeating everything and picking up multiple new words daily.
- He began stringing words together, saying things like “What’s this?” and “More, please!”
- He even combined spoken words with signs, forming short phrases in mixed modalities.
By 26 months, his vocabulary growth accelerated even more.
- He moved from simple phrases to 3- and 4-word sentences.
- He started singing songs.
- The speed at which he picked up words visibly increased.
You can clearly see the shift in the data, also.
Why Hearing Plays a Key Role in Speech Development
One reason I wanted to share this on a blog focused on sound is because hearing is a crucial element of spoken language learning.
When evaluating speech delays, speech-language pathologists (SLPs) always ask about hearing tests and ear infections. Why? Because frequent ear infections can temporarily affect hearing, making it harder for a child to distinguish syllables and word nuances. This is one reason why children with recurrent ear infections may have a higher risk of speech delays.
If you suspect a speech delay, don’t wait to seek an evaluation. Early language challenges compound over time, so even small interventions can make a big impact. Speech therapy for young children is typically play-based and fun, making it an easy and positive experience.
Want to See Another Language Burst in Action?
If you’re curious about another great example of a language explosion, check out this father who tracked his son’s first words. His child’s language burst started right at 18 months, closely aligning with the research. (Special thanks to Reddit user Jonjiv for sharing how he tracked his data and created his charts!)