An overview is provided of the history of English as a second language (ESL) instruction, including a discussion of second language acquisition and the characteristics of ESL instructors and students. The first sections provide an overview of the major language learning methodologies that have been most often associated with the adult as a second-language learner in general and an ESL learner in particular. Discussions are presented of the history, use, and problems associated with: (1) the first methods of second language learning, which involved memorization of verb conjugations, translations of passages, and reading and writing of language rules; (2) the audio-lingual method (ALM) of teaching second languages, which replaces the focus on writing and reading with an attempt to teach aural-oral language skills; and (3) methods introduced by Caleb Gattegno and Charles A. Curran, which stress the process of language learning and the psychological dynamics involved. Next, the paper focuses on the changing role of the adult learner in the ESL setting, including material on the role of the language instructor. A discussion of the relationship between linguistic, sociolinguistic, and psycholinguistic concerns leads into a description of functional/notional instructional approaches to syllabus design and a review of methods of personalizing ESL instruction. Finally, major changes in ESL instruction over the past two decades are summarized and considerations for the future are explored. (EJV)