О способности взрослых изучать слова и грамматику по сравнению с детьми см., например: Ellen Bialystok and Kenji Hakuta, In Other Words: The Science and Psychology of Second-Language Acquisition (New York: Basic Books, 1994); James Emil Flege, Grace H. Yeni-Komshian, and Serena Liu, «Age Constraints on Second-Language Acquisition,» Journal of Memory and Language 41 (1) (1999): 78–104.