All of what we call language is the process of tagging the tagging of perceptions and of tags themselves.
Any sentence can be broken down into five types of operation – Tagging a perception of an object or action (you can’t tag them directly), tagging a tag, tagging an instance of tagging a perception, tagging an instance of tagging a tag, and tagging an instance of tagging an instance. I think that is it.
So a noun is the tagging of the perception of an object.
A verb is the tagging of the perception of an action or state of an object.
An adjective is tagging an instance tagging a perception of an object.
An adverb is tagging a verb or adjective style tagging instance or another adverb instance.
… and so on.