I don’t spend all that much time in the children’s section of the bookstore, so I guess I oughtn’t to be surprised that I never noticed this series of books. It’s called the “Words are Categorical” series, in which children are taught that words fall nicely and neatly into categories. Everything’s a verb, or a noun, or an adjective, or one of a few other parts of speech. These divisions are completely natural, and clearly distinguishable.

I disagree with all three of these claims, and I’m going to follow up the Preposterous Apostrophes series with a new series about the non-categoricality of parts of speech. This is by no means an uncontroversial or decided point, and in fact it happens to be my main line of current research. For instance, consider cleaning in The couch needs cleaning. Try to come up with a principled reason why this word is either clearly a verb or clearly a noun.

As it turns out, non-categoricality is rampant in language, and I’ll try to both justify this claim and explain its consequences in future posts.