Linguista: Jurnal Ilmiah Bahasa, Sastra, dan Pembelajarannya Vol.4, No.2, Desember 2020, hal 114 - 119 ISSN (print): 2579-8944; ISSN (online): 2579-9037 Avaliable online at: http://e-journal.unipma.ac.id/index.php/linguista  114 DOI: http://doi.org/10.25273/linguista.v4i2.7797 Morphological Awareness: Students’ Proficiency in Analyzing Derivational Affixes in English Efrika Siboro and Barli Bram * Universitas Sanata Dharma, Jalan Affandi, Mrican, Sleman, Yogyakarta 5528, Indonesia e-mails: efrikasiboro@gmail.com; * barli@usd.ac.id Abstract This paper examines students’ proficiency in analyzing derivational affixes in English. The objective of this research is, then to discover how far the students’ capability in analyzing the errors of prefixes and suffixes in English sentences. The researchers limit the study to focus only on derivational affixes. To obtain the data, the students were tested. The participants of this research were undergraduate students of the English Education Department at STKIP Pamane Talino, West Kalimantan. The researchers used a descriptive qualitative method to analyze the data. The results show the average of students’ proficiency in analyzing prefixes and suffixes in sentences is 68.57%. More specifically, seven students (33.33%) belong to the “excellent” category, seven students (33.33%) belong to the “very good” category, four students (19.04%) are categorized as a “good” category, two students (9.52%) are classified as a “fair” category, and one student (4.76%) belongs to the “poor” category. Keywords: derivational affix; students’ proficiency; word-formation. Introduction Vocabulary is a fundamental part that should be learned by students to master a language. According to Alqahtani (2015); Asyiah (2017); Hernawati (2015); Kacani & Cyfeku, (2015); Viera (2017) stated vocabulary can be defined as an essential element of a language which encourages and helps a learner communicate well. It indicates if a learner has a limited vocabulary, he will not be able to communicate fluently. Thornbury (2002) argued vocabulary can be divided into several aspects namely parts of speech, polysemes, word formation, collocations, and homonyms, for example. In this regard, the researchers will discuss word-formation. In word-formation, there is a term called affixation. Affixation is a morphological process which consists of the attachment of affixes to the bases to generate new words (Alhasibunur, 2016; Herman, 2015; Subandowo, 2017; Tambusai, Nasution, Widayati, & Jufrizal, 2016). Zainuddin (2016) stated affixation has an important function in word formation because it can change the meaning of a word. For instance, affix -ness will change an adjective like “kind” into the noun “kindness”. Furthermore, affixes are related to bound morphemes and free morphemes (Bunau & Yusof, 2018; Genon- Sieras, 2020; Najjari & Mohammadi, 2016; Rizki & Zakrimal, 2020; Tariq et al., 2020; Turjoman, 2016; Yastanti & Warlina, 2018). A free morpheme refers to a morpheme which can stand alone for example sit, drink, date. While bound morpheme is a morpheme which cannot stand alone independently (Genon-Sieras, 2020; Kazemian & HAshemi, 2014; Luthfiyati, Kholiq, & Zahroh, 2017; Martini, 2016; Maulidina, Indriyani, & Mardewi, 2019; Nurjanah, Ramdhaniah, & Efransyah, 2018; Ramadan, 2015; Rugaiyah, 2018). A bound morpheme is usually called affixes which consist of prefixes, infixes, and suffixes but in English, there are only two types of bound morphemes,