Human beings have as great a capacity for losing or forgetting a language as they do for learning one. Many have lost language skills due to a lack of a linguistically appropriate environment in which to use a particular language. Millions of individuals who have studied a second language in high school or college for several years have lost the ability to hold the most basic conversation, while others who as children or young people were monolingual speakers of other languages are now monolingual speakers of English, for they are no longer able to speak their mother tongue. Language acquisition and maintenance depend on a variety of factors including the following: (1) instructional factors that relate to the way in which the language is initially acquired, including instructional objectives, intensity of instruction, developmental considerations, and curriculum design; (2) cultural factors that relate to how public attitudes toward bilingualism and the relative prestige of different languages influence the maintenance of a particular language; and (3) personal factors that have related and correlated certain personality traits positively with success in learning foreign languages. Language study that helps the student to use the personal and cognitive strategies used by "expert learners" will enhance the likelihood of language skill maintenance; courses of study in which positive cultural attitudes are fostered and in which maintenance techniques are incorporated will help to prevent attrition. (TR)