The paper analyses the potential of blended assignments that incorporate an online discussion forum component in English for Specific Purposes (ESP) courses taught at the university level. The analysis includes various types of blended assignment design and a range of specific intralinguistic mediation strategies, as defined in the revised CEFR (2020). Accordingly, the paper presents three case studies based on a questionnaire survey conducted among university students and a content analysis of their English language production. The first case study explores students’ perceptions of online discussion forum dynamics within different blended assignment designs. The second case study compares forum components with a focus on discipline-specific content versus ethical issues. The third case study examines the interconnection of two distinct professional communities—healthcare staff and transport specialists—through a blended assignment involving an online discussion forum. The outcomes of this small-scale investigation suggest that such assignments hold considerable potential for developing relevant English language skills, particularly in the area of mediating profession-specific content.

Keywords: ESP, online discussion forum, intralinguistic mediation, blended learning.