Vocabulary and grammar are crucial to language proficiency. Certain word families and grammatical categories are differentiated by prosodic features like suprafixes. In English, specific noun/adjective-verb pairs, often called disyllabic words, have primary stress on different syllables: nouns usually receive trochaic stress, while verbs receive iambic stress. Research shows that suprafixes present challenges for language learners from diverse linguistic and prosodic backgrounds. Given the limited research on Turkish EFL learners, this study investigated their knowledge, perception, and production of suprafixes. Participants were B1-level preparatory school students from a prominent state university. Data were collected using a knowledge test (n = 110), a perception test (n = 80), and a production test (n = 50). Results indicated poor suprafixational knowledge, perception, and production among Turkish EFL learners. Minor gender differences in suprafixational competence were observed, with various noun-verb pairs challenging both genders. The study concludes that Turkish EFL learners require targeted suprasegmental training focusing on suprafixes.