The article analyzes the difficulties encountered by 5th-grade students in the process of reading and understanding compound sentences connected by negative conjunctions. The research was conducted in three stages: in the first stage, experimental materials consisting of various sentence types were compiled, and the comprehension level of compound sentences with negative conjunctions was assessed; in the second stage, students’ contextual comprehension skills were examined on the basis of negative conjunctions used within a text; in the third stage, their ability to interpret a compound sentence with a negative conjunction presented independently of context was tested. The results show that students make significant errors in fully grasping the meaning of the negative construction “neither…nor.” These errors were found to negatively affect the holistic understanding of the text. The study highlights the role of negatively connected compound sentences in reading comprehension competence and offers important methodological conclusions for mother-tongue education.