Why can infants and young children learn a second language more easily than teenagers?

Infants and young children can learn a second language more easily than teenagers primarily due to their brains having greater plasticity. Brain plasticity refers to the brain's ability to reorganize itself and form new neural connections throughout life, which is especially pronounced in early childhood. This means that young children's brains are highly adaptable and responsive to new information, making them particularly adept at acquiring new languages.

During the critical period for language acquisition, which extends through early childhood, children's brains are particularly primed to absorb language sounds, structures, and vocabulary almost effortlessly. This capability allows them to pick up a second language with much less conscious effort compared to teenagers, whose brains have begun to stabilize and are less flexible when it comes to new language learning.

While factors such as exposure to language, memorization techniques, and distractions can influence language learning, the unique neural flexibility present in young children is the key reason for their enhanced ability to acquire new languages at such an early age.