Analysis the Use of Inflectional and Derivational In Students’ Writing Maria Olga Jelimun 1 , Benedikto Cahya Dharma 2 , Fitriyeni Irma Jemalu 3 {olgajelimun@gmail.com 1 , dictdikta11@gmail.com 2 , fitriyenijemalu@gmail.com 3 } 1-3 Universitas Katolik Indonesia Santu Paulus Ruteng, Indonesia Abstract. This research uses a qualitative descriptive method with a survey design to analyze the use of morphemic processes, classification and categorization of derivational and inflectional morphemes in students' writing. The research focused on abstracts of scientific articles written by fourth semester students at the Indonesian Catholic University, Santu Paulus Ruteng, with a sample size of 15 students. The 15 students were selected based on their writing results which were in accordance with the criteria. The research instrument is documentation of student writing. The results showed that students' articles mostly consisted of three categories of morphemes that were widely used. First, in the noun category there are 176 occurrences involving the transformation of verbs into nouns or adjectives into nouns. Second, students demonstrate the use of morphemes that change nouns into adjectives. Third, students use morphemes that change adjectives into adverbs. In addition, students also used inflectional morphemes, with the inflectional morpheme “- s” mostly used to indicate the plural form of nouns in their articles. Furthermore, they use the inflectional morpheme “-ed” to indicate the past tense in their writing. Effective use of these morphemes contributes to the clarity and accuracy of students' writing. Keywords: Article; derivational; inflectional; morphology 1 Introduction Language meaning and language meaning related to linguistics are combined to form linguistics. Put differently, linguistics is linked to the exchange of language-related data, which is important for its subfields. The study of linguistics focuses on the complex processes involved in language. It is impossible to isolate the rapidly expanding area of linguistics from other equally significant disciplines like politics, law, social studies, literature, culture, and psychology, among others [1]–[5]. This is so that, in addition to studying language products as independent entities, the linguistic orientation may also look into the ways that society as a whole facilitates social interaction [6]–[8]. "The theoretical and empirical investigation of real-world problems in which language is a central issue" is what Brumfit defined as applied linguistics. This implies that the engineering of linguistics is applied linguistics. Stated differently, applied linguistics is the application of linguistics to real-world issues. The study of language in detail is the subject of a subfield of linguistics known as micro-linguistics. It describes language as a separate and distinct natural phenomenon [9]. Micro-linguistics directs the study of a particular language's internal structure as well as the internal structure of languages generally. Furthermore, the field of linguistics known as micro- linguistics studies language from within, or from the viewpoint of the language itself. In today's world, English has become increasingly vital for effective international communication and ICEHHA 2023, December 15-16, Ruteng, Indonesia Copyright © 2024 EAI DOI 10.4108/eai.15-12-2023.2345630