This paper analyses the epistemological status of the relationships between Applied Linguistics and Educational Linguistics, as well as the possibility of some boundary areas or "Middle-earth" between them, and the problem of identifying and defining Glottodidactics as an autonomous science. The analysis reflects the debates in Italian academic circles arising from new perspectives in psycholinguistics, sociolinguistics and language pedagogy, the most notable of which were Acquisitional and Educational Linguistics.