This thesis proposes an ontological delimitation between events, facts and states of affairs. It does so from a Platonist/realist perspective. It also relates the logic ontology to language use through the analysis of reference to these entities. Events, facts, and states of affairs have been present in the discussion of analytical philosophy from the times of Frege. However, the discussion still continues, and nothing has been defined. Events have been reduced to objects, facts and states of affairs. Facts have been reduced to states of affairs and propositions. States of affairs and facts have been considered as the same entity by some authors, and so forth. These three entities have been associated to language since the times of Russell (1918). Facts were related to true statements, and were understood as entities to which those statements pointed. Events were related to action sentences. According to Davidson (1981a), we have action sentences because there are events in the world. Though this thesis relates ontology to language, it defines ontology independent of language use. That is, ontology is defined without taking language use into account. It proposes that the difference between events, facts, and states of affairs is that the first are concrete, and the last abstract. Among other characteristics. Once we define the ontology, we relate it to language use through reference. We analyze whether it s possible to refer to events, facts, and states of affairs, because we understand that it is through reference that we may establish the relationship between ontology and linguistics.