The research is aimed to determine the contribution of Information
Technology (IT) students’ attitude and level of familiarity in using
English loanwords in bahasa Indonesia toward their English vocabulary
mastery. The type of research was a correlational study of contribution.
The research population was the fifth-semester students of IT in the
academic year 2018/2019 at IAIN Bukittinggi with the total number of
population was 180 students. The sample selection was done by using
cluster random sampling technique with the total of the sample was 45
students from 6 parallel classes. The research data were obtained from
attitude questionnaires, familiarity level questionnaires, and English
vocabulary test. These instruments were analyzed statistically by using
simple and multiple regression with a significance level was 0.05.
