This study investigates how secondary school students perceive the stylistic register of selected discourse connectives in Czech, combining experimental research with corpus-based frequency analysis.

In the field of discourse analysis, style plays an important role in shaping the way information is communicated and understood. The stylistic appropriateness of discourse connectives is important in maintaining coherence and clarity within a text. Connectives not only function to link ideas and arguments but also reflect the stylistic register of the discourse. The validity of these connectives is contingent upon their alignment with the overall tone, formality, and communicative intent of the discourse, thus ensuring that the flow of ideas is both seamless and contextually appropriate.

Classification of discourse connectives as formal, neutral, or informal is often based on linguistic intuition rather than systematic study. Understanding how native speakers, particularly students, interpret these stylistic distinctions is important for both linguistic research and pedagogical praxis, especially in teaching text cohesion, register awareness, and academic writing skills.

In the experimental part of the study, secondary school students assessed the stylistic markedness of selected connectives, indicating whether they perceived them as formal, neutral, or informal. The results reveal notable patterns: while some connectives show high agreement among respondents, others exhibit significant divergence in perception. We present detailed voting distributions and variance calculations, highlighting which connectives students classify consistently and which ones cause uncertainty. These findings provide insight into the intuitive stylistic categorization students develop during their education and linguistic exposure.

To complement this, we analyze the authentic usage of the connectives in different registers using corpus data from the SYN2015 (written Czech) and ORAL_v1 (spoken Czech). We compare the relative frequencies of the connectives across fiction, academic literature, newspaper texts, and spoken discourse, assessing whether students' perceptions align with actual language use. In some cases, students classify connectives as formal despite their frequent occurrence in informal contexts, suggesting discrepancies between perceived and empirical stylistic norms.

From a pedagogical perspective, these findings highlight the need for explicit instruction in register awareness, particularly in helping students develop a more accurate understanding of linguistic variation. The study underscores the potential benefits of integrating corpus data into language education to provide learners with empirical evidence of stylistic usage. Moreover, the results contribute to refining teaching strategies for text cohesion and stylistic appropriateness, supporting students in mastering effective written and spoken communication.

Keywords: Discourse, cohesion, discourse connectives, stylistic register, corpus linguistics, secondary school students, Czech.