Major Parts of Speech

According to the contemporary consensus, when reaching in the lexicon grammar looks for items like nouns, verbs, and prepositions while logic sees items like predicates, connectives, and quantifiers. In fact, there doesn't seem to be a single lexical category contemporary grammar and logic both make use of. I hope to show that while a perfect match between the lexical categories of grammar and logic is impossible there can be a substantial overlap. I propose semantic definitions for all the major parts of speech (noun, verb, adjective, and adverb). I argue that the differences among these categories can be captured in terms of distinctions recognized in logic (referring expression vs. predicate, constant vs. variable).