Language for Specific Purposes (LSP) has been primarily used to refer to two areas within applied linguistics: 1) one with a needs-based educational/ training focus; and 2) one with a focus on research on language variation across a particular subject field. A third approach, content/ theme-based language instruction (CBI) has also been confused with LSP. These several uses of the label of LSP have caused some confusion internationally.

LSP is most widely applied to an approach to second/ foreign language teaching and training addressing immediate, very specific needs of learners who need language as a tool in their studies/ training or on the job. Needs analysis is the underlying “driver” for the development of LSP programs. (Hutchinson & Waters 1987, Robinson 1980, Swales, 185, 1992, Hyland 2002) For example, English native speaking nurses, working in hospitals with a high frequency of Spanish native speaking patients, might study Spanish for very specific nurse: patient communication needs. LSP can be used with any target language that learners need as a tool for very specific purposes. It has been most widely applied to English, English for Specific Purposes (ESP).

Language for Specific Purposes has also been used to refer to a branch of applied linguistics which deals with a variety of language used by members of a particular subject field, concentrating on its genres, stylistic features and technical lexis. This research is relevant for such problem-based areas as language education, translation and the design of specialised dictionaries. Some in the training area consider such research on Professional Communications as LSP-related research when it is paired with/ applied directly to an LSP training program.

Content-based language instruction (CBI) is also sometimes confused with ESP. At the post-secondary level it is frequently used to motivate groups of learners who may be interested in the same professional field, providing meaningful communication opportunities. However, as in their regular studies they are usually not studying through a foreign/ second language (except for sheltered courses), they do not need English as a tool in their immediate studies. “Content-based instruction (CBI) is the integration of selected content with language teaching aims” (Brinton & Snow 2002, Brinton, Snow, Wesche 1989). Thus, when trying to identify which approach being taken, it is critical to ask, “Is it English for Specific Purposes or English through specific content themes or content areas?"