Spanish se-constructions have many readings. The emphasis of this paper lies on the passive and the impersonal readings, which do not exist in German or English. I show that both constructions contain implicit information, contrary to previous analyses of se in the impersonal construction as an overt. In order to account for the constructions, I assume systematic operations that concern different grammatical levels, actually lexical conceptual structure (LCS), argument structure, and functional structure. The correct analysis for the derivation of the se-constructions discussed here can be formulated adequately within Lexical Mapping Theory (LMT), the Lexical Functional Grammar linking module.