ABSTRACT
The earliest known Greek grammar by Dionysius Thrax distinguishes eight parts of speech: noun, verb, participle, interjection, pronoun, preposition, adverb, and conjunction. The list looks largely familiar to the modern eye, though there are certain surprises. A number of categories that play a role in modern taxonomies-article, auxiliary, classifier, complementizer, determiner, etc.—are missing. Some of the traditional categories appear too narrow: participles, prepositions, and pronouns are typically viewed by contemporary linguists as subcategories of adjectives, adpositions, and nouns, respectively. When it comes to interjections, there is a serious question whether they should count as genuine words at all: greetings, expletives, fillers, and the like are at best loosely integrated into sentences. But in the larger scheme, these are quibbles: we continue to classify words roughly the same way as we did around 100 b.c. Given that, it is striking that there is no agreement about the underlying principles of classification.
