The present paper focuses on two Czech syntactic structures formed with the reflexive clitic 'se', namely semantically reflexive verbs and so-called reflexive verbal form (RVF), and explains their syntactic properties assuming the generative model of language. The analysis is based on the hypothesis that verbal and nominal projections are analytic, i.e. containing the functional categories v and D (Chomsky 1995). Moreover, it is claimed that the derivation may proceed in several phases, which are fed by different modules of grammar, namely Dictionary and Syntacticon (Emonds 2000). The core assumption of the paper is that the clitic 'se' is a defective grammaticalized element that is inserted from the Syntacticon and enters the syntactic derivation only after the Case was assigned. Nevertheless, it does so necessarily before Spell-Out in order to be correctly interpreted at LF. The syntactic properties of semantically reflexive verbs and the RVF then naturally follow on the assumption that the clitic 'se' occupies the complement position of semantically reflexive verbs and the subject position of the RVF.