Theoretical linguistics is the branch of linguistics that inquires into the nature of language or languages without regard for practical applications (see applied linguistics for the latter). Theoretical linguistics is concerned with constructing theories of language or languages, or with developing linguistic theory.
- "Briefly, theoretical linguistics studies language and languages with a view to constructing a theory of their structure and functions and without regard to any practical applications that the investigation of language and languages might have, whereas applied linguistics has as its concerns the application of the concepts and findings of linguistics to a variety of practical tasks, including language-teaching." (Lyons 1981:35)
Some linguists have said or implied that theoretical linguistics implies the study of language in general, and that the study of particular languages does not constitute a kind of theoretical scientific inquiry (i.e. that descriptive linguistics is not a kind of theoretical linguistics). However, it is commonly agreed that it is reasonable to say that constructing a description of a language is tantamount to creating a theory of that language. Moreover, theoretical is a good term to be used in contrast to applied.
- Lyons, John. 1981. Language and linguistics: an introduction. Cambridge: Cambridge University Press.