The bilingual brain: why children learn languages with ease

A child’s brain in the early years of life exhibits extraordinary plasticity, allowing them to absorb new information with remarkable ease. Among the most notable capabilities is the natural and intuitive acquisition of a second language, which fully leverages the neural flexibility typical of infancy. Early exposure to multiple languages is not only possible, but also highly beneficial from a cognitive, emotional, and relational perspective.

The neurobiological basis of early language learning

In early childhood, the cerebral cortex—the part of the brain responsible for processing language—is still highly malleable. During this time, the brain processes multiple languages using a single neural network, which enables simultaneous acquisition without confusion or overlap. As children grow older, this plasticity diminishes, and second language learning tends to engage distinct brain regions, making the process more complex and less intuitive than in infancy.
This shift explains why language acquisition is generally more challenging and less fluid for adults: the mature brain is less adapted to managing multiple linguistic systems simultaneously.

Language competence begins in the womb

Numerous studies confirm that a fetus can perceive and retain linguistic sounds during pregnancy. The mother’s voice plays a particularly important role in stimulating the baby’s auditory brain areas. When both parents are bilingual, the child begins developing the ability to distinguish between two languages even before birth—even when the languages are structurally very different (e.g., Italian and Japanese). When languages are more similar (e.g., Italian and Spanish), differentiation might take a few more weeks but still occurs within the first few months of life.

The “Sensitive Window” for language acquisition

The period between birth and around 7–8 years of age is considered a sensitive window for language learning. During this time, children are especially receptive to sounds, grammar structures, and linguistic patterns, and can acquire two languages in parallel with exceptional proficiency, even with native-like pronunciation.
After this period, the ability to attain native-level fluency in a second language typically decreases, although learning remains entirely possible. For this reason, early and consistent exposure to multiple languages is a unique and valuable opportunity.

The parents’ role in early bilingualism

A bilingual home provides the ideal setting for the simultaneous acquisition of two languages. A common and effective strategy is for each parent to consistently speak their own native language. This clear distinction helps the child naturally separate the two linguistic systems and develop both sets of skills in a balanced way. Differences in tone, rhythm, and intonation between the two parental voices further assist the child in acoustically navigating the two languages.

It’s important to note that any initial delay in verbal expression among bilingual children is usually normal and temporary. It does not reflect cognitive difficulties but rather a short-term adaptation to managing a higher linguistic load. These differences typically resolve on their own over time.

Long-term cognitive benefits

Multiple studies show that early second language acquisition not only enhances linguistic abilities but also promotes broader cognitive development. Bilingual children tend to:

• develop greater mental flexibility;
• strengthen their working memory;
• improve selective attention and problem-solving skills;
• benefit from a higher cognitive reserve, which may support healthier brain aging in adulthood and later life.

Childhood is the ideal time to learn a second language, thanks to the brain’s plasticity and children’s natural inclination for communication. Early exposure to multiple languages—especially within a secure and emotionally rich environment—is a valuable investment in a child’s intellectual, linguistic, and social development. Parents play a central role in this journey and, with the right support, can offer their children a lifelong advantage.