This master's thesis explores the conversational discourse of high school students from Šibenik. The beginning of the paper emphasizes the importance of understanding the distinction between style and discourse, introducing the reader to the concept of discourse, encompassing both conversational style and discourse. Conversations of five different groups of high school students, specifically from four different high schools in Šibenik, were analyzed. The research aimed to analyze their speech in both oral and written forms, focusing on the phonological, morphological, and syntactic levels. The assumption was that the greatest number of deviations from the standard would be present at the phonological level, which proved to be accurate, with vowel reductions being the most common deviation. The analysis of the written form also revealed the presence of reductions. The written form also indicates frequent sending of short messages or sentences without much context, yet understandable among high school students. Additionally, the lexical level, including jargon and colloquialisms, was examined through a survey conducted among the students. The results of this research contribute to understanding the characteristics of conversational discourse among high school students in Šibenik and their use of linguistic forms that differ from the standard language. However, it should be noted that the research was conducted among a small number of students (compared to the total number of high school students in Šibenik), which limits the generalizability of the results. Future research can confirm (or refute) the findings obtained in this study.