If Betty is significantly taller than Jane, I can truthfully say either “Betty is taller than Jane” or “Betty is tall compared to Jane.” However, if Betty is only one millimeter taller, things are different. I can only truthfully utter that Betty is taller than Jane. It is no longer the case that Betty is tall compared to Jane.
This is a linguistic pattern, one where our judgment of which sentences are true is influenced by the grammatical constructions we choose. As a linguist, I study patterns like these. I analyze them using various types of logic and basic algebra with the goal of creating a formal theory that accurately characterizes the piece of the mind/brain that produces these types of judgments: our language faculty.
Figuring out what is an accurate characterization involves weighing many different factors. First, the formal theory must be able to generate the pattern. Second, we must have an adequate explanation of how people come to acquire these patterns. Third, we must keep in mind the range of different possible patterns that exist across all natural languages. Our final theory should be fairly easy to acquire yet flexible enough to explain all possible patterns in all possible languages.