The benefits of applied linguistics This paper offers examples from three areas of applied linguistics showing that the relation between linguistics and applied linguistics is bidirectional: not only does applied linguistics utilize the results of linguistic research but descriptive and theoretical linguistics too can rely on applied linguistics. The huge databases established and managed by language technology can reveal hidden correlations within the language system. The area of applied linguistics known in Hungary as nyelvmvels 'language cultivation', which offers advice on issues concerning the (more fastidious) linguistic norm, is an important source for diachronic linguistics, as non-linguists who point out newly emerging "linguistic errors" (and the linguists who respond to them) are the first to observe the changes taking place in the language. Language acquisition research, i.e. the study of the language use of younger children, may call attention to linguistic constraints that go unnoticed in the language of adults.