The article discusses the speech act of disagreement, implemented with the help of the word net (no/not). The source of the material for the analysis is the Sound Corpus of oral everyday Russian speech “One Day of Speech”. The analysis revealed various types of implementation of the speech act of disagreement. It turned out that such acts realized with the help of the word net often violate the politeness principle and can lead to a communicative conflict between interlocutors. The results of the research can be useful for improving communicative skills of speakers of Russian and other languages.