This article presents a study carried out in the area of distance learning electronic forums. Based on the relevant bibliographic review, electronic forums are increasingly becoming part of the learning process. The specific study was stimulated by previous works relevant to the modelling of the behaviour of IT students at Hellenic Open University (HOU) and addresses the issue of distance learning forum modelling using a formal language, aiming to fill the gap that exists in this area, which is demonstrated by the relevant bibliographic review. For this purpose: (a) a relevant note was submitted to HOU's forums, (b) the main concepts of formal languages were specified, (c) a formal language was created which was specified using mathematical terms and represents the messages of HOU's forum, (d) the correctness of such language was verified using specific examples of its function, (e) a language syntactic check algorithm was designed, (f) the parameters impacting on the effectiveness of a distance learning forum were determined, (g) concepts such as time, group size and volume of information were incorporated into the language and (h) efforts were made to identify the factors impacting on the effectiveness of a distance learning forum and the following concepts were incorporated: time, group size and volume of information, in the language. (Contains 3 tables and 3 figures.)