The topic of my thesis is the subjunctive mood in Slavic languages, which is a subject that has not received sufficient attention in theoretical linguistic literature so far. Even though Slavic languages do not feature dedicated subjunctive verb forms, Slavic subjunctives can be distinguished from indicatives because they are introduced through distinct clause-initial items. This observation led to the claim that subjunctive and indicative complements in Slavic correspond to two different embedded clause types, selected under formally distinct CP projections. Indicative CP was argued to constitute a marked syntactic option in embedded clausal environments, in the sense that it is selected by a specific group of predicates which share a common lexical feature, whereas subjunctive CP is selected as a default embedded option, by predicates which do not contain the relevant feature. This analysis allowed me to account for the lexical diversity of predicates that select the subjunctive in Slavic.