Is there a Critical Period for Acquiring a Second Language?

The Critical Period Hypothesis (CPH) predicts that native-like proficiency is unattainable in adult L2 learning due to gradual (with age) loss of neuroplasticity. This essay reviews a number of studies that examined ultimate attainment by late
(after puberty) L2 learners. These learners were able to overcome the CPH predictions because of some linguistic factors, like the influence of the L2 learners’ mother tongue, and the access to Universal Grammar (UG), as well as non-linguistic ones, like the age of arrival and the length of residence in the L2 environment, aptitude (verbal and analytical abilities), and motivation (need for communication and integration). Given these findings, we conclude that maturational constraints may be counteracted by various mental and psychological resources.