ABSTRACT This paper addresses the role of input and interaction and attitudes and motivation on second and foreign language acquisition. Through the case study of an American English learner of Polish, the paper examines classroom instruction in the United States and the “natural” learning situation of living in the target language country. Long (26) has suggested that most research in second language acquisition addresses the direct impact of a variable on SLA, and has called for more research to investigate variables that have an indirect effect on SLA. This paper suggests that input and interaction are triggers for positive attitudes and motivation and thus are indirect, rather than direct, contributors to second and/or foreign language acquisition. Finally, the author explores the implications of input and interaction as triggers for SLA on language programs and language classrooms.