Exploring the Factors and their Effects on ESP Students' Low Language Performance

English for Specific Purpose (ESP) courses are usually taught in almost all disciplines in universities to help students develop their English proficiency in relation to their respective fields of study. Sometimes these courses happen to be quite challenging and cause learners either to fail in the ESP courses' exams or to gain very low marks. Hence, the present study aimed to explore the factors and their effects on students’ low language performances in these courses. A quantitative research design was applied where 100 participants were chosen from departments of physics, chemistry, biology, and mathematics in Education Faculty at Badghis Institute of Higher Education. Two types of questionnaires were used as data collection instruments. The results showed three main factors that strongly influence the low language performance of participants in ESP courses. These factors included the students' English background, ESP textbooks, and the teaching methodology of the ESP teachers.