We back J.C. Moreno's proposal (J.C. Moreno 1991a, 1991b, 1997) on event analysis, although we also have considered other very similar approaches (Pustejovsky, 1995; Tenny and Pustejovsky, 2000).
The events expressed by verbs can be of three major types, forming a universal hierarchy (J.C. Moreno, 1997) of states, processes and actions. These three types are divided into subtypes according to the arguments they require.
This approach is compositional: a state has two arguments, a process is made up of a transition from one state to another, and an action is a process with an agent. This leads to the logical consequence that we need an annotation format for representing both the relation between events and the arguments of the sentence and their sub-event structure.
Most of the recent work on semantics focuses on ontologies. It is important to distinguish the fact that SESCO does not have an ontology as a basis, but that the ontology can be a result of our work.