Stephen Krashen, born 1941, is professor emeritus at the University of Southern California, USA. Stephen Krashen received a PhD in linguistics from the University of California, Los Angeles, in 1972. Krashen's numerous papers and books have greatly contributed to the fields of second language acquisition, bilingual education and reading. What follows is an interview with Krashen by 21st Century staff Peng Lun and Ma Shuang.