 Newport and Supalla) show that, rather than abrupt changes in SLA ability after puberty, language ability declines with age, coinciding with declines in other cognitive abilities, thus supporting Piaget.Although Krashen (1975) also criticises this theory, he does not deny the importance of age for second-language acquisition.Krashen (1975) proposed theories for the close of the CP for L2 at puberty, based on Piaget's cognitive stage of formal operations beginning at puberty, as the ‘ability of the formal operational thinker to construct abstract hypotheses to explain phenomena’ inhibits the individual's natural ability for language learning.