Can babies learn more than one language from birth? Yes, no problem!

Multilingualism in childhood: Developing the ability to communicate proficiently in more than one language

Multilingual children regularly hear more than one language and develop multiple systems of communication to engage with and learn about the world around them. These kids take a little bit longer than monolingual children to become proficient since they are building two (or more!) language systems at once. However, one study found that, when the number of unique words known by multilingual children is combined across languages, they have similarly-sized vocabulary as monolingual children. Generally, bilingual and monolingual children follow the same developmental processes: first learning single words and growing their vocabulary, then using two-word combinations and starting to explore their use of verb tenses. Learning multiple languages at once does NOT actually delay children’s cognitive or linguistic development– that’s a myth!

Differences between multilingual and monolingual children’s development

Although they follow the same developmental stages, multilingual and bilingual children have some different language-learning behaviors. The period of universal discriminability is the window of time in which infants can differentiate speech sounds from all languages, and studies show that it’s a little bit longer for babies hearing multiple languages. Monolingual infants consistently hear just one language, so they are able to more quickly specialize in the sounds necessary for language-specific contrasts. Multilingual infants hear multiple languages, each with their own unique sounds, so it takes them longer to specialize in the unique properties of both languages from the wider range of sounds they hear. Young children learning two languages at once often switch between languages within a sentence or conversation, a phenomenon known as code-switching. For example, they might say “Mama, agua please!” combining the Spanish word for water with the English word “please.” The ability to blend multiple language systems shows a deep understanding of both systems’ grammatical rules.

A baby with brown skin and curly black hair sits reading a book with the title, "First 100 words." The baby wears a black and white horizontally-striped hoodie and jeans and has furrowed their brow in concentration.
Young children can learn multiple languages at once with regular exposure– no books required!

When learning new words, monolingual and bilingual babies pay attention to different parts of the world around them. Monolingual kids think of nouns as names for physical objects, and they generally attend to the features of an object when learning the new term. In contrast, bilingual kids may think of nouns as contextually-specific tools to talk about objects. This difference occurs because bilingual kids learn two words for one item. Each name is used in a different situation, depending upon the language being used. Learning the appropriate context for each noun is crucial to successfully using it. For example, a monolingual, English-speaking child may know that the word “ball” describes a round object that they sometimes use to play catch. However, after a child who speaks English and Spanish learns that both “ball” and “pelota” refer to this object, they have to use more contextual clues from the speaker to figure out which word to use to describe the round toy. Scientists hypothesize that paying more attention to context may be necessary to help bilingual children combine all of the situational cues needed to correctly add the new vocabulary word to their language system.

Though multilingual children differ from monolinguals in some of the ways they learn language, the previously-held belief that multilingualism makes learning hard is not true. Research has shown not only that there is no deficit in overall vocabulary but also that there are actually many benefits to learning multiple languages, such as improvement in various executive functioning skills. 

Alt, M., Arizmendi, G. D., Gray, S., Hogan, T. P., Green, S., & Cowan, N. (2019). Novel word learning in children who are bilingual: Comparison to monolingual peers. Journal of Speech, Language, and Hearing Research, 62(7), 2332-2360.
Beardsmore, H. B. (2008). Multilingualism, cognition and creativity. International CLIL Research Journal, 1(1), 4-19.
Berens, M. S., Kovelman, I., & Petitto, L. A. (2013). Should bilingual children learn reading in two languages at the same time or in sequence?. Bilingual research journal, 36(1), 35-60.
Colunga, E., Brojde, C., & Ahmed, S. (2012). Bilingual and monolingual children attend to different cues when learning new words. Frontiers in Psychology, 3, 155.
Ferjan Ramírez, N., Ramírez, R. R., Clarke, M., Taulu, S., & Kuhl, P. K. (2017). Speech discrimination in 11‐month‐old bilingual and monolingual infants: a magnetoencephalography study. Developmental Science, 20(1), e12427.
Genesee, F. (2010). Dual language development in preschool children. Young English language learners: Current research and emerging directions for practice and policy, 59-79.
Hayakawa, S., & Marian, V. (2019). Consequences of multilingualism for neural architecture. Behavioral and Brain Functions, 15(1), 6.
“Multilingualism.” Zero To Three, Zero To Three, 2017, 
Okal, B. O. (2014). Benefits of Multilingualism in Education. Universal Journal of Educational Research, 2(3), 223-229.
Valdés, Guadalupe. “Multilingualism.” Linguistic Society of America, Linguistic Society of America, 

Taylor is laughing and looking at the camera. She wears a grey and white t-shirt, has light skin, and curly light brown hair. The clue blue sky and some grass are visible in the background.

Taylor Horowitz


Taylor is a senior majoring in neuroscience and minoring in biology and chemistry. After Duke, she hopes to attend medical school. Taylor is interested in learning about how children’s environments influence their ambitions and goal-setting, both academically and socially. Here at Duke, she also does research through Bass Connections on the topic of global neurosurgery. In her free time, Taylor enjoys running, having picnics, singing karaoke, and eating cereal.

Elika Bergelson

Principal Investigator