The key to understanding is precision—writing precisely and reading precisely. Language, though, is not mathematics: a word can mean many things while a numeral cannot, and so there are times when we may think we understand what a writer is saying, but a closer look reveals otherwise. Here’s an example: This is a collection of essays which, we believe, is representative of the many ways to understand the role of art in society. What exactly is representative, the essays or the collection of essays?
Let’s affirm first that there is no grammatical complaint to be made about this sentence, and I am not hauling it under the lights to point out where its flaws lie. It could be polished up, true, but it illustrates nonetheless how closely—and with a sure knowledge of how English grammar works—we must read sometimes. Here that means understanding the form and function of what are called relative pronouns. Pronouns are the part of speech which stand on behalf of (hence the prefix pro-) a noun; without them, we would drive one another to distraction by having to repeat the same noun over and over, or be forced constantly into finding a synonym, which would eventually send our thoughts off course. By most counts, English grammar recognizes five kinds of pronouns, and there’s no writing English of any sophistication without the relative pronoun.
A pronoun always (or almost always) has an antecedent, the word or phrase or clause before it to which it refers. Relative in the term relative pronoun means carried or referred back (just as familiarly we have our relatives), and so to understand what any relative pronoun means, we must look back in the sentence to see where the pronoun came from. There are three basic relative pronouns in English: who, which, and that. Some of these have other forms (whose and whom), and the whole topic—let’s admit it—can get, shall we say, involved. What we need to know to understand our example, though, is that the pronoun which can only point to an inanimate entity, some thing instead of some one.
Now in that part of our example sentence that precedes the relative pronoun which, there are two nouns which could be its antecedent, essays and collection. Each of these, though, is an inanimate thing, and so how are we to determine which of them the writer meant? A first quick reading of the sentence might very well have led us to believe that the essays were representative of the many ways to understand art; that, after all, is the last named noun before the relative pronoun, and our natural (not logical) inclination is often to see as related what is merely associated. A closer look, though, will reveal that essays cannot be the antecedent of the relative pronoun which here because the verb working with that relative pronoun is singular, not plural: which is representative, not which are.
Verb agreement always clinches the deal, and that singular verb is makes it incontrovertibly true that the writer was making a claim for the collection of essays he was presenting, not a claim for the essays themselves. That is a precise, or close, reading, and it’s important just because it is both exact and revealing. No one essay could have practicably represented the full array of opinions about art in society, and so the writer would not have written what he meant had he used a plural verb with the pronoun. The representativeness, so to speak, is to be found in reading all the individual essays he gathered into the collection, some arguing one point of view about the role of art, and another, another.
Language is not as precise in all its forms as mathematics (or perhaps I should say as arithmetic), and just for that reason we often have to look for other structural cues, like the number of the verb, to sort out a possible confusion. Call it sorting out or reading closely, therein lies the richness of thinking.