Foreign language acquisition is notoriously constrained by learners’ lack of awareness of the systemic relations that are obtained among stable multiple-unit lexical items. This results in learners’ inability to variegate their performance (both written and oral) with idioms that stand in complementary (synonymy) or contrastive (antonymy) distribution to one another. Nor are learners typically able to distinguish between the multiple senses of English idioms. Given these impedimenta, the present research investigates the degree of entrenchment of idiomatic synonymy, antonymy, and polysemy and, on the back of it, sets the agenda for partial revision of the practice of exposing learners to English idioms. Data were collected to investigate the knowledge of idiomatic synonymy, antonymy, and polysemy amongst Russian EFL learners. The results of the ANOVA analysis revealed that the degree of awareness of the major types of idiomatic paradigmatic relations significantly differed between the groups, with learners being more aware of synonymy and polysemy than antonymy. The findings suggest that current EFL materials and dictionaries need to be updated and revisited with a view to exposing foreign learners to an extended network of paradigmatic idiomatic relations.