Novianti. 2020. Teaching Derivational Suffixes To Increase Students‟ Vocabulary at the First Grade SMAN 3 Luwu Utara ( Supervised by Sri Damayanti and Opik Dwi Indah).

The objective of the research is to find out the students‟ teaching derivational suffixes to increase students‟ vocabulary at first grade SMAN 3
LuwuUtara. The research used pre-experimental method. The population of this
research was the first grade SMAN 3 Luwu Utara in academic year 2020. The
total number of the sample was 22 students. The researcher used random sampling
in determining the sample. To get the result of data analysis, the researcher used
SPSS version 20. The researcher input the data pre-test and post-test used SPSS
version 20. Based on the data analysis it is found that teaching derivational
suffixes is one of the method to improve vocabulary the students‟ easy. It is
supported by achievement of the mean score in the pre-test is 43.18 and the mean
score in the post-test 68.41. It means that students have a good understanding in
learning derivational suffixes. So, it is concluded that teaching derivational
suffixes can increase the students‟ vocabulary.