The document summarizes Stephen Krashen's theory of second language acquisition and reports on a study that tested his theory. Krashen believed that older children acquire a second language faster than younger children. The study compared a 13-year-old girl (Subject A) and a 7-year-old boy (Subject B) who both grew up speaking Yap but were exposed to English at different ages. Analysis of a 10-minute recording found that Subject A communicated in more complex sentences with better grammar compared to Subject B's simple responses, supporting Krashen's theory. However, factors like shyness or distractions could have influenced the results.