Semi-Auxiliary Modals are lexico-grammatical means which contribute to updating various modal meanings as elements of Compound Verbal Predicate. The status of semi-auxiliary verbs has been a motif of a debate for more than half a century and it has beneficiated a various interpretations depending on the method applied and point of view of researchers. The value of semi-auxiliary modal verbs as component element of the compound verbal predicate in the Romanian language syntax was proved by scientists as V. Guţu Romalo, Gh. Nedioglu, P. Dumitraşcu, C. Săteanu, C. Dimitriu, D. Irimia, Ec. Teodorescu, D. Craşoveanu, S. Berejan, A. Ciobanu, N. Mătcaş e.t.c. The present paper deals with evolution of studies in this field suggesting a new opinion concerning the list of semi-auxiliary modal verbs in Romanian language and their classification in semantico-functional fields according to the expressed modal meanings. A more detailed view of the semantico-functional field has been presented, it consisting of the folloing semi-auxiliary modals: a trebui, a fi, a se face, a urma, a rămâne which can update other modal meanings except necessity as well as the verbs: a se cuveni, a se cădea, a se cere, a se impune, a rezulta which express a just meaning of necessity being appreciated as contextual semi-auxiliars. The evolution of the language points out the fact that some more structures are out-of-date (a trebui infinitive), others do not correspond to the rules (a trebui supin) and some of them are used more frequently.