The aim of this research was to know the students' problems in mastering
vocabulary by the second semester students of English Education Department
University Muhammadiyah Purwokerto in academic year 2018 2019. This study
used descriptive quantitative study. The writer took 50% of the population as the
sample. The total number of students is 111 students. Therefore, the writer takes
55 students as the sample of the research. The data were collected using test and
questionnaire, the result of which was analyzed using percentage. The finding of
the test shows that: the students’ difficulties were in word classes (38%),
homonym (41%), homophones (33%), homograph (21%), polysemy (62%),
affixation (44%), synonym (61%), antonym (60%), and word formation (50%).
While the finding through the questionnaire shows that: the factors of students'
difficulties in learning English vocabulary were: - rarely practicing new
vocabulary (27%), laziness to check difficult word in dictionary (70%), laziness to
memorize English vocabulary (55%), laziness to read text book or article in
English (75%), feeling difficult to memorize a similar vocabulary (75%),
unsupporting environment to practice English (35%), mother tongue influence
(38%), and the last self in confidence and last motivation (45%).