Class consciousness

So what's the alternative to the old "parts of speech" model? Schoolhouse Rock provides a handy clue: "conjunction junction, what's your function?" -- what if we were were to ask of other words, not what it is they are, but what it is they do? The answer would give us word classes, which have the tremendous advantage of describing what English words actually do do in actual sentences and utterances. Some of these classes, such as the class of prepositions or that of conjunctions, are relatively stable -- these are sometimes called "closed" classes -- but in other cases -- what the parts people call nouns, pronouns, verbs, adjectives, and adverbs -- a word's class status might be completely different depending on the particular sentence it's in. In addition to words such as fish, photograph, taste, and service -- all of which can potentially be members of several classes without changing their form at all (these are called zero morphs) we also have a wide array of suffixes, and sometimes prefixes, that "recruit" a word from one class to another: -able turns verbs into adjectives (love ==> lovable); -ment turns verbs into nouns (govern ==> government); and of course -ly turns adjectives into adverbs (quick ==> quickly).