The purpose of the article is to provide a semantic and comparative analysis of Serbian and Russian markers of ‘consent’, which form a part of the lexical-syntactic and pragmatic macrocategory of ‘affirmation’. All the analyzed markers have been divided into four groups constituting two semantic classes. The structure of the semantic category of ‘expressing consent’ is argued to comprise the semantic class ‘confirmation’, made up of ‘truthfulness’ and ‘compliance’, as well as ‘acceptance’; further divided into ‘willingness’ and ‘permission’. The semantic classes differentiated in this way correspond to types of modality: confirmation/epistemic modality and acceptance/deontic modality. The analysis of language markers of the semantic category of ‘expressing consent’, making part of the macrocategory ‘affirmation’, has been carried out in the onomasiological perspective.