Impact of Derivational Morpheme Teaching on Vocabulary of the Students Learning Turkish as Foreign Language

This research was carried out to reveal the impacts of derivational morpheme teaching on vocabulary of the students learning Turkish as a foreign language, and the research was performed with the use of quasi-experimental design with pre-test and post-test control group, which is one of the quantitative research methods. The study group of the research consists of 26 foreign students learning Turkish at B2 level at Ondokuz May？s University in 2016-2017 academic year. The application process of the research was carried out within the last 8 weeks until the completion of the educational program for the students at B2 level, which started on April 3, 2017 in Turkish Teaching Practice and Research Center at Ondokuz May？s University. The collected data and analyses have shown that the students learning Turkish as a foreign language benefited significantly from the derivational morpheme teaching, that the vocabulary of the experimental group improved more effectively than the control group. It has also been determined that learners' success in terms of vocabulary was influenced by the origin and structure of their native languages. As a result of the detailed analysis carried out on the data, it has been found out that the improvement in the vocabulary of the students from the experimental group was recorded as 88 words in average (30.98%) according to the evaluation made on 284 words, that the impact of the experimental practice on this improvement was calculated as 62.4 words (21.97%), and that the derivational morpheme teaching made contribution to the vocabulary of the students at the rate of 1.06% per each derivational morpheme