The present paper offers (i) a logico-semantic analysis of sentences of the form "(ιx)Φ(x) is C“, where C stands for „possible“ (LP) or „merely possible“ (MP) or „really possible“ (Re) or „impossible“ (NP) and (ii) an explication of intuitive meanings of these expressions using modal temporal semantics. The crucial question concerning this analysis runs: What are the items to which modality C is attributed in these sentences? Is it an individual that is the referent of the description "(ιx)Φ(x)“ or an intension generated by the meaning of the description or the meaning of the description itself? It is argued that the most suitable response is the last one. Unlike some other positions, the present view has it that possibilia are not individuals but meanings of individual descriptions that have referents only at world-time couples "w, t" where w is not the actual world. Being a possibilium amounts to being the meaning of a description having the property MP that is defined as follows: (ιx)Φ(x) is MP iff (ιx)Φ(x) is possible, but there is not exactly one individual having the property (λx)Φ(x) at some world-time couple "aw, t" where aw is the actual world. Apart from the concept of possibilium, another concept of semipossibilium (SP) is introduced namely the meaning of a description which except some referents in the actual world has also at least one referential pause in this world (i.e. time interval at which the description has no referents). The first part introduces (i) the notions of semantic reference and user’s intentional reference, (ii) the difference between the actual world and the real world and (iii) the definitions of LP, MP, Re and NP modalities. The second part tries to answer the question whether the intension or meaning of a description is a suitable subject of predication in sentences which have the form "(ιx)Φ(x) is C“. The rest of this part deals with possibilia and semipossibilia.