The Resource Description Framework is based on the SPO paradigm. The SPO paradigm is drawn from the knowledge representation community and well suited to express complex coherencies in a formal way. Three typical sentences can be made with SPO.
[Subject] has [Predicate] [Object]
or [Object] is [Predicate] of [Subject]
or [Predicate] of [Subject] is [Object]
For further information refer to http://www.w3.org/TR/REC-rdf-syntax.