This paper presents an online concordancer that was created at the Applied Informatics department for teaching and learning of French language. It also contains examples of possible activities for teachers and students that can be used in the educational process. Besides tools specifically developed for learning and based on classical theories of language teaching, information technology offer other fundamentally new resources and tools that can be used in the educational process. Corpora are the most important resources that are not yet fully utilized in language teaching. The most difficult problem is the effective use of corpora. The contribution of TAL (Traitement Automatique des Langues / Natural Language Processing) is necessary for the development of tools and methods which simplify use of corpora. The concordancer is one of such tools. It can effectively process large amounts of text and reveal the necessary elements: keywords, phrases or grammatical constructions.