Grammar (analogy) is the "heart" of the Trivium.   It is the subconscious recognition of the structure of a technological environment.  And it is far more than simple “sentence diagrams” (noting that Chinese doesn't actually have subject/predicate sentences, alerting us to the differences involved).  Furthermore, treating technologies as “languages” (as Marshall McLuhan did in his 1956 essay, “The New Languages”), we are unavoidably caught in a matrix of grammars – with fundamental impact on how we live our lives.  Our interaction with these grammars shapes our behaviors and attitudes, imbuing us with our subconscious biases, and providing us with the “premises” for our arguments, which we often resist changing.