October 26, 2026
Think back to your child's first babble, the first time they said a word you recognized, or the day they strung two words together and looked at you, proud of themselves. These moments stay with us. They're also signs of one of the most remarkable things happening in early childhood: a brain that's especially open to language.
Many parents have heard that the preschool years are a window for language. That can sound exciting, but it can also sound like pressure. Is the window closing? Am I doing enough? Should my child be speaking more by now?
In this article, we'll look at what researchers mean by a sensitive period for language, what it might look like in your child day to day, and simple, playful ways to make the most of it. Most of these fit easily into the routines you already have. The short version: you don't need flashcards or special programs. What helps most is something you already give your child every day, which is real connection.
The idea of sensitive periods goes back a long way. Over a century ago, the Italian physician and educator Maria Montessori noticed that young children seem to go through phases when they're especially drawn to certain kinds of learning. Language was one of the clearest.
Modern neuroscience backs up much of what she saw. Research by Patricia Kuhl and colleagues at the University of Washington has shown that babies start out able to tell apart the sounds of nearly every language in the world. Kuhl has called them citizens of the world. Somewhere around the end of the first year, babies get better at the sounds they hear around them and less sensitive to sounds they don't hear. Their brains are tuning in to the languages of their home.
One of Kuhl's best-known studies showed something important for parents. When nine-month-old babies from English-speaking homes spent time playing with a Mandarin speaker in person, they kept their ability to hear Mandarin sounds. Babies who heard the same Mandarin from a video or audio recording did not. Live human interaction mattered.
Other work points the same way. The Harvard Center on the Developing Child describes serve and return exchanges, the back-and-forth between a child and a caring adult, as the foundation of healthy brain architecture. A 2018 study led by Rachel Romeo at MIT found that the number of conversational turns children experienced was linked to brain activity in language areas, more strongly than the total number of words they heard.
It's worth being clear about this. A sensitive period isn't a critical period that slams shut. People keep learning language their whole lives, including new languages as teenagers and adults. During early childhood, though, the brain picks up sounds, rhythms and grammar with unusual ease, often without any formal teaching. That's why these years are such a good opportunity. It doesn't mean there's only one chance.
Every child develops at their own pace, and the range of what's typical is wide. Some children talk early and nonstop. Others listen and take things in for a long time, then suddenly speak in full sentences. Both paths are common. Here's a general picture of what you might notice:
Many families in Santiago, and many at Runningbrook, raise children with two or more languages. If that's your family, you might see some extra things that are completely normal:
Research by Ellen Bialystok and others has also linked bilingualism to strengths in attention and flexible thinking. Learning more than one language is an asset, not a burden.
Culture shapes language too. In some families, children are encouraged to chat with adults at the dinner table. In others, children mostly learn by watching and listening, and talk more with siblings and cousins. Some homes are full of books, while others pass on stories, songs and sayings out loud from grandparents. All of these are rich language environments.
The good news is that supporting language doesn't take special equipment or extra time. It happens inside the moments you already share. Here are five ideas you can try today.
Remember those conversational turns? Even with a baby, you can take turns: your baby coos, you answer, then you pause and wait. With a toddler who points at a dog in the park, you might say, Yes, a big dog! It's running fast. Where do you think it's going? Then give them time to answer, in words, sounds or gestures. That pause is where the learning happens.
Getting dressed, cooking, walking to the market: these are all chances for language. Now we're putting on your blue socks. One sock, two socks. Brrr, it's a cold morning! This kind of self-talk wraps words around real experiences, and that's how meaning sticks.
Shared reading is one of the most widely recommended ways to support early literacy, and it doesn't have to follow the text. Point at pictures, ask what might happen next, or make up your own version. Songs, finger plays and nursery rhymes in any language help children hear the rhythm and sounds of speech. If one picture book gets requested twenty times in a row, that's fine. Repetition is how children learn.
If your family speaks more than one language, talk to your child in the language you feel most comfortable and expressive in. Children gain the most from rich, warm, natural language, the kind you use to joke, comfort and tell stories. Keeping your home language strong also protects your child's connection to grandparents, culture and identity.
A cardboard box that becomes a bus, a toy kitchen, a pretend phone call with grandma: pretend play is full of language. Children invent characters, negotiate roles and tell stories. Join in sometimes, follow their lead, and resist the urge to correct every word. If your child says I runned, you can simply reply, You ran so fast! Modeling the correct form gently works better than pointing out the mistake.
One more note: research consistently finds that young children learn language best from people, not screens. That doesn't mean screens are forbidden. When they're part of your family's life, watching together and talking about what you see turns screen time into shared time.
At Runningbrook International Preschool, our child-centered approach and play-based learning are built on the same principles the research highlights. Since 1993, we've seen how children's language grows when they feel safe, valued and free to explore.
In each program, from Growing Steps to Pre-Kinder, our educators follow each child's interests and pace. We know that a child who's quiet today may be absorbing everything, and that confidence is one of the strongest drivers of language. When children feel good about themselves, they want to communicate.
Every child is unique. Some differences in language development are just part of normal variation, and bilingual children may follow a slightly different timeline. If something about your child's communication worries you, trust that instinct and talk to your child's educators or pediatrician. Getting support early is a positive step, never a failure.
The preschool years really are a special window for language. That window is filled with ordinary moments: lullabies at bedtime, chatting in the car, laughing over a silly rhyme, answering the hundredth why? of the day. You don't need to be perfect or do more. Being present, responsive and yourself is enough.
And remember, you are the expert on your own child. You know their sounds, their gestures, their favorite words and the stories they love. That knowledge is the best foundation there is. At Runningbrook, we're glad to walk alongside you as your child finds their voice, in one language, two, or many.