EN
This paper investigates Arab EFL learners’ acquisition of modal verbs. The study used a questionnaire, which comprises two versions, testing students’ mastery of modals at the levels of both recognition and production. The questionnaire was distributed to 50 English major university students who had studied English for 12-14 years and who had scored 500 or more on the TOEFL. The findings of the study show that the overall performance of the subjects in the study was quite low. The study established a hierarchy of difficulty and identified the major causes of difficulty in the use of modals.