“It was good of you to look for Quentin.”
“Good!” she exclaimed. “Good! O Anthony!”
“Well, so it was,” he answered. “Or good in you. How accurate one has to be with one’s prepositions! Perhaps it was a preposition that set the whole world awry.”
—Charles Williams, The Place of the Lion
Anyone who struggles to articulate why an event may be viewed in person or on television but not on person or in television will agree, prepositions can make one want to smack one’s palm against, on, or at one’s head.
Before we master prepositions we must, of course, master the concepts they describe. This is not trivial. By about three or four months, infants demonstrate some understanding of concepts like “above,” “below,” “right,” or “left.” More specifically, infants will habituate to (that is, become exceedingly bored by) a series of pictures in which a dot is always positioned on one side of a horizontal or vertical bar. Once the dot moves to the other side of the bar (as opposed to moving a similar distance but remaining on the original side), infants regain some interest: after so much “above,” “below” looks pretty good. But it takes an additional three to four months before infants can generalize these relationships—to understand, that is, that the “above” relationship between a dot and a bar is identical to the same relationship between a triangle and a bar, or a dot and a row of asterisks.
Concepts like between, which describe a relationship among three entities instead of two, take an extra few months to learn and generalize. And all of these relationships—specific or generic—would almost certainly take longer to classify in the real world, which is dauntingly (and annoyingly) more complex than any stimuli an experimenter is likely to dream up.
Once we’ve learned the concepts, we can label them. Most infants’ earliest words are nice, tangible things—objects like Daddy, doggy, and milk that can be pointed to and slobbered over. Surprisingly, though, prepositions aren’t far behind, sometimes finding a place among a child’s first 20 words (though often in isolation, and used as commands—think of a child demanding “Up!” or “Down!”).
Knowledge about a few prepositions may usher along the rest. Knowing how “above” and “below” behave in sentences, for instance, may make it possible to learn rarer prepositions like “throughout.” In a study led by University of Illinois researcher Cindy Fisher (also my current postdoc advisor), two-year-olds sat in front of two televisions positioned side by side. Children watched multiple videos of a hand placing a toy duck on top of a box. Each time, children heard either This is a corp! or This is acorp my box!, depending on condition. Then during the test phase, one television showed a different object—a pair of eyeglasses—being placed on top of the box. On the other television, a new duck was placed beside the box. The children were asked to decide What else is a corp? or What else is acorp my box?
Children with large vocabularies who’d heard a corp preferred the video with the new duck, suggesting that they’d interpreted a corp as a noun phrase, e.g. “a toy duck.” High-vocabulary children who’d heard acorp my box, on the other hand, preferred the video with the eyeglasses, which had the same spatial relation to the box as did the original ducks, suggesting that the children had interpreted acorp as a preposition, e.g., “above.” (Two-year-olds with a relatively low vocabulary did not differentiate between the two conditions.) In other words, the structure of the sentence guided children to attend to the relationship between objects instead of the objects themselves.
Of course, just because a child understands a preposition in its most literal, spatial sense does not mean she’s mastered its usage—ask any English second-language learner. But there are blessedly a fixed number of prepositions, the nuances of which are possible to learn if by no means than sheer memorization.
