The aims of the research were to find out : 1) type the error by students’ in using
preposition. 2) the dominant errors made by students in using preposition by the
second year students of SMK Muhammadiyah 1 Purwokerto in academic year
2016/2017 It was a descriptive research in which the total sample was 60 students
( class XI ). The data was collected by conducting 25 test questions. The finding
showed that students made many error in prepositions and the typical errorr that
occured in using preposition (at, in, on ) were error of selection ( 93 % ) and
second level is insertion ( 7 % ).