I remember speaking a word whose meaning I didn’t know but about which I had some inkling, some intuition, then inserting that word into a sentence, testing how it seemed to fit or chafe against the context and the syntax, rolling the word around, as it were, on my tongue. I remember my feeling that I possessed only part of the meaning of the word, like one of those fragmented friendship necklaces, and I had to find the other half in the social world of speech. I remember walking around as a child repeating a word I’d overheard, applying it wildly, and watching how, miraculously, I was rarely exactly wrong. If you are five and you point to a sycamore or an idle backhoe or a neighbor stooped over his garden or to images of these things on a television set and utter “vanish” or utter “varnish” you will never be only incorrect; if your parent or guardian is curious, she can find a meaning that makes you almost eerily prescient—the neighbor is dying, losing weight, or the backhoe has helped a structure disappear or is glazed with rainwater or the sheen of spectacle lends to whatever appears onscreen a strange finish. To derive your understanding of a word by watching others adjust to your use of it: Do you remember the feeling that sense was provisional and that two people could build around an utterance a world in which any usage signified? I think that’s poetry. And when I felt I finally mastered a word, when I could slide it into a sentence with a satisfying click, that wasn’t poetry anymore—that was something else, something functional within a world, not the liquefaction of its limits.