Grammar, it can be helpful to remember, is not arithmetic. That may seem cold comfort, but it means that not every grammatical question has only one right answer. We write and speak to communicate our mind, to say how we see things from where we stand. The choices we make in sentence structure and punctuation determine our perspective, and so sometimes very small detail will contribute consequentially to what exactly we’re telling the reader.
Or should I have written very small details? A student of mine struggles mightily with knowing when to use certain nouns in the singular or the plural. Broadly, his questions on this topic fall under the heading of collective nouns, which are nouns whose singular form defines a group of similar items; so we speak, for example, of an orchestra or jury. There is no such thing as an orchestra of one musician or a jury of one person, and so when we pluralize nouns like these, we are multiplying the groups, conceptions which already refer to multiple individuals. We might then say, for example, that London has many fine orchestras.
Nouns like orchestra and jury denote factually certain multiplicities, but others are not quite so sure, and so we have choices to make, choices that will reveal the manner in which we are conceiving the situation we are writing about. My student recently brought to our session a sentence like the following, and he wanted to know whether the noun concern could, or should, be used here in the plural: I told him he needed to balance his concern for his company and his personal health. His question was a good one, but he kept tightening his perplexity by thinking arithmetically about the problem, rather than perspectively. You go to the store to buy half a dozen eggs, and I go to buy six. The difference lies not in the number of eggs we each return with, but in how the same action is conceived: you bought one thing and I bought six.
Let’s take up our grammatical tools and isolate the portion of the sentence in which the question arises: to balance his concern for his company and his personal health. The phrase to balance is an infinitive being used as a noun (it’s what someone needed), but because infinitives are built from verbs, they have many of the same properties as their verbal source, one of which is to take objects. So the noun concern is the object of the infinitive to balance. Right here, then, is the question we need to ask: does the writer conceive of the noun concern as a flood of mental attention directed over a wide area, his company and his personal health, or does he understand it to be a laser-like light focused on two individual things, his company and his personal health? The answer to that question will determine whether the noun should be singular or plural.
To see this better, observe that the nouns company and personal health stand as two objects for the one preposition for. There is nothing unusual about this, but the writer did have another choice, to repeat the preposition for each object: for his company and for his personal health. Repeating the preposition would have differentiated the two entities more acutely, suggesting that each should be the object of an individual effort of careful consideration. In that case, it would have been better to pluralize concerns in order to heighten this idea of distributed attention. And this might very well have been how the writer was conceiving the thought, because the verb balance, earlier in the sentence, suggests the weighing of two things. We would then have had this sentence: I told him he needed to balance his concerns for his company and for his personal health.
As the sentence stands in the original, though, we are to see that someone’s concern should be poured over an aggregate of company and personal health, two entities blended as one object of interest. Which is correct? That question is what is not correct. Although our decidedly scientific and indicative predisposition would like to quantify all of life, the question of perspective—how one sees a situation—remains. This does not negate objectivity and throw all perception into a relative subjectivity, but rather adds a playful twist to it, which sometimes requires us to tease out, with indeed a judicious amount of that same scientific habit, just what the objective grammar is suggesting. All the better, then, when between yes and no there’s sometimes a maybe.