Critical Period Hypothesis

The Critical Period Hypothesis suggests that there is an optimal window in early childhood during which the human brain is particularly receptive to acquiring language. If a child isn't exposed to language within this period, their ability to learn it fluently—and sometimes their overall language skills—may be significantly limited later in life. This window is thought to be related to brain plasticity, which is highest during early development. After this critical period, learning a new language or achieving native-like fluency becomes more difficult, although not impossible.