by Dana McDaniel 

When babies are born, they don’t speak or understand any language. But by the time they’re 6 years old, they speak the language or languages of their community almost as fluently as adults. How do they learn to use such a complex system in such a short time?  

If you ask adults how babies learn language, they usually answer that babies learn language by imitating their parents. But if you ask children how they learned language, they often answer that they just got older. It turns out that the children’s answer is closer to the truth! 

It’s true that babies often like to imitate adults. If you smile at a baby, the baby will smile back; and if you say a word, the baby will sometimes repeat it. But babies and young children often say things that are not repeated – they say words when they want to and they make their own sentences. Also, there is no way we could learn everything we know of our language by imitating our parents. By age 6, children understand around 20,000 words and speak in grammatical sentences.  

Words also can’t be learned just from imitation. Imitating words like wonder or seem or of aren’t going to tell you what the words mean or how to use them in a sentence. And even learning a word for a concrete object like car is much more complicated than it seems. Suppose that a baby’s parent points to a car and says “car.” You might think that the baby can learn the meaning of the word that way. But how does the baby know that the word refers to the car and not to something else, like the pointing action or the color of the car?  

It turns out that babies (and older children and adults) use certain strategies to learn words. One important strategy is to pay attention to sentence structure. For example, if you don’t know the word wonder and you hear someone say, “I wondered why the boy was smiling,” that tells you that wonder is a word that is similar to the word ask because the word ask also fits in that place: “I asked why the boy was smiling.” 

So how do babies learn sentence structure? The answer is that the human brain is set up for language. It may even be that babies are born with a general language grammar and just need to fill in the specifics for the language or languages of their community. Before they are even a year old – before they actually say any words – they have learned which sounds their language uses and they already recognize grammar words, like the in English. 

Even though the baby’s brain is set up for language and they learn a lot on their own, it is still very important for parents to talk to their babies as much as possible. Interacting with adults helps babies learn words and develop communication skills. 

Dana McDaniel is Professor of Linguistics at the University of Southern Maine. Her research focuses on syntax/sentence structure and child language acquisition. She’s most interested in the nature of language in the human mind.