Postmodern insights rewritten as verifiable and useful statements.
The Wikipedia article on Postmodernism has an excellent definition:
Postmodernism is a movement away from the viewpoint of modernism. More specifically it is a tendency in contemporary culture characterized by the problematization of objective truth and inherent suspicion towards global cultural narrative or meta-narrative. It involves the belief that many, if not all, apparent realities are only social constructs, as they are subject to change inherent to time and place.
Recasting those sentences as three simple statements creates an even better definition: 1) Objective truth is problematic. 2) Many apparent realities are only social constructs. 3) Global cultural narratives (Absolutes) should be treated with the utmost suspicion.
(Another way to say global cultural narrative: "A narrative that remains valid in every local culture." So far I have yet to see one of those.)
All three of these statements are open to verification. Also it is useful to know whether these statements are true and false.