In this little treasure, the world s leading second-language acquisition theorist expounds in brief his hypotheses, most notably that comprehensible input results in language acquisition. He proposes what he believes constitute the components of an effective foreign language program at various stages of acquisition, emphasizing ways to provide aural comprehensible input as well as reading. He deals with various practical issues, among them differences between foreign-language programs and second-language programs as well as activities that are effective for bringing about true competence in a second or foreign language and activities that are not.