Baby holding their belly

The Endless Benefits of Multiple Language Exposure in Babies

Ever wonder why it's much harder to learn a second language as an adult?

Spanish? French? Chinese? There is mounting evidence that children benefit from growing up in multilingual households. Whatever foreign language(s) you pick for your baby, here’s what science says about learning a second (or third) language from infancy. 

Early Exposure to Language

In the womb, your babe is already listening to your voice. In fact, it is one of the most important sounds they hear prior to birth.  By the time they are born, your baby can differentiate between the language of the mother (that’s you) and different languages (might be you too). In fact, language differentiation is one thing your baby can do better than you. At birth, a baby can tell the difference between all 800 sounds that make up the languages of the world.

Fun fact: There are roughly 6,500 languages spoken in the world today. Only 23 languages make up more than half of the world’s population.

Each language uses about 40 sounds, or “phonemes.” A baby brought up in a monolingual household– a house where just one language is spoken– will quickly figure out which language they are hearing first and start to specialize in that language between 6 to 12 months. In part, that’s happening because the mind is learning to become more efficient. 

See related: The Four Stages of Speech Development in Children 

At birth a baby’s brain has roughly 100 billion neurons. (About as many nerve cells as there are stars in the Milky Way.) This is almost all the neurons the brain will ever have. The cerebellum and the prefrontal cortex will continue adding new neurons in infancy. (Another reason why nutrition is so important during the first 1,000 days of life.) The hippocampus is the only known area of the brain that will continue to add neurons, and interestingly, is the area  of the brain involved in learning and memory.

Brain Development and Multilingual Babies

Here’s where it gets really interesting for new parents– especially those interested in a multilingual household. If you recall from science class, synapses are brain structures that allows the neurons to transmit a signal to another neuron. Synaptic pruning is a natural process that occurs in the brain between early childhood and adulthood. During synaptic pruning, the brain eliminates extra synapses.

Language synapses that are not being used will start to prune away as early as 9 months. Thusly, by their first birthdays, babies are beginning to lose their ability to hear the differences between foreign sounds. 

In one study of 11-month-old infants raised in English-only homes versus bilingual homes, researchers found that the babies in the bilingual, or Spanish and English-speaking homes were specialized to both languages. The babies from the English-only homes were specialized just to English. Learning two languages at once did not hinder the bilingual babies’ ability to adopt either language. 

Your Baby Is Smarter Than You Think

Parents often wonder if exposing infants to multiple languages will delay their ability to master a language.  Certainly, a parent focused on just one language will have more time to expose a child to the many words of that particular language. Whereas a parent who is teaching multiple languages must divide their time between the vocabulary of several languages. However, bilingual children have been found to ultimately have an equal or greater vocabulary versus their monolingual peers. There is also evidence that the early acquisition of multiple languages primes the brain to have better executive functioning skills, such as problem solving and attention shifting. 

TIP: Teaching language is shown to be far more effective when taught through interaction with real people. Watching an instructional video, even a screen with someone talking, is considered less effective. 


Hoff E, Core C. Input and language development in bilingually developing children. Seminars in Speech and Language. 34: 215-26.

The Norwegian University of Science and Technology (NTNU). “Babies exposed to stimulation get brain boost.” ScienceDaily. ScienceDaily, 2 January 2017. <>.

Moon, C., Lagercrantz, H., & Kuhl, P. K. (2013). Language Experienced in Utero Affects Vowel Perception after Birth A Two-Country Study. Acta Paediatrica, 102, 156-160.

Kluger, Jeffrey. “How the Brain Benefits from Being Bilingual,” (18 July 2013).


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