We investigated age-related decline in adult learning of Dutch as an additional language (Ln) in speaking, writing, listening, and reading proficiency test scores for 56,024 adult immigrants with 50 L1s who came to the Netherlands for study or work. Performance for all four language skills turned out to decline monotonically after an age of…

Foreign language aptitude is defined as one's potential to learn a second language. A language learner with higher aptitude is predicted to learn more, faster, and reach a higher level of proficiency. If this is the case, one way to validate the construct of aptitude and its measure is to conduct a validation study in which measures of aptitude is…