Diah Ayu KARTIKA Pengarang Nadia Sya'ya, M.Pd., M.TESOL Dosen Pembimbing 2 Bahrani, M.Pd. Dosen Pembimbing 1

Diah Ayu Kartika, 2020. “ An Analysis of Inflectional Affixes on English Department Undergraduate Students’ Thesis Abstract of IAIN Samarinda in Academic Year 2019/2020”.S1 Thesis, study program of English Education Department, Teacher Training and Tarbiyah Faculty, State Islamic Institute of Samarinda. This Research is under guidance of Bahrani M.Pd as the advisor I and Nadia Sya’ya M.Pd., M. TESOL as advisor II. Inflectional Affixes is one of the morphological studies. Those affixes are adding to express the grammatical categories without change the class of word. It is important to learners knowing about inflectional affixes because learning about the structure the language does not only occur in sentence but also in a word. The objectives of the research are to find out what are the types the inflectional affixes that found and which one the inflectional affixes that the most dominant found on English department undergraduate students’ thesis abstract of IAIN Samarinda. The researcher used descriptive qualitative research design. The subject of this research was 36 undergraduate students’ thesis abstract in 2019. The main instrument of this research is the researcher herself. The technique of collecting the data is finding the thesis document in campus library. The technique of data analysis that the researcher used in this research is identification, classification, tabulation, and description. Based on the finding the data, The researcher concluded that there are eight categories of inflectional affixes. The first was inflectional verb, they are suffixes (-s,-es,-ies) 7,9% as present tense marker, suffixes (-d,-ed,-ied) 25,3% as past tense marker, suffix (-ing) 26,3% as progressive aspect marker, and the suffix (-en) 2,2% as past participle marker. The second was inflectional noun, they are suffixes (-s,-es,-ies) 33,6% as noun plural marker and suffixes (-‘s, -s’) 5,5% as noun possessive marker. The third was inflectional adjective, they are comparative marker (-er) 0,5% and superlative marker (-est) 0,6%.Thus, the most dominant affixes that found was suffixes (-s,-es,-ies) as plural noun marker 33,6%.