THE STUDENTSí ABILITY IN USING DERIVATIONAL SUFFIXES IN WORD FORMATION
This study is aimed to describe the students ability in usingderivational suffixes in word formation. Word formation is one of the importantaspects in vocabulary building because the students can know how to create new
words through kinds of processes, by using compounding, blending, clipping,acronyms, affixes, etc. The design of the research is descriptive quantitative.This study assigned 58 students of the second semester of English Department
in academic year 2014/2015 as the population and sample of the study. Data ofthis study were the students scores in vocabulary test about derivationalsuffixes used in word formations. The vocabulary test as the instrument of the
study was in the form of written test in the type of short essay test. Relying ondescriptive quantitative design, the data obtained were analyzed by usingdescriptive statistics which were focused on mean score and rate percentage.
The research revealed the following findings: (1) The students ability in usingderivational suffixes in word formation of the second semester of EnglishDepartment of University of Kutai Kartanegara in academic year 2014/2015
was good. This fact was supported by the students mean score was 67.89 whichwas on B grade (good level); (2) The scores distribution of the studentsability in using derivational suffixes in word formation of the second semester of
English Department of University of Kutai Kartanegara in academic year2014/2015 were in five criteria ranged from A to E grade. It was found that 11or 18.97% of the students got A (excellent) level, 2 3 or 39.66% of the
students obtained B (good) level, 15 or 25.86% of the students gained C (fair)level, 6 or 10.34% of the students got D (poor) level, and 3 or 5.17% of thestudents got E (failed) level. It meant that from 58 students, 49 or 84.49% were
successful, and 9 or 15.51% of the students were fail in using derivationalaffixes in word formation.
Keywords: Affixes, Derivational Suffixes, Word Formation, Ability, Vocabulary Building