Every art has its procedure, its way of doing business. The art of writing—or call it the art of composition or of thinking—lays out grammar as its way forward, with signposts and guardrails to keep the force of one’s thinking (the old word for it was mentation) accumulating forward. One such critical guide stipulates whether the verb is singular or plural with certain words called indefinite pronouns.
Pronouns are one of the eight parts of speech in the traditional scheme of grammar, and indefinite pronouns are a subclass whose members refer not to a specific antecedent already named (for example, the dog was barking because he was hungry, where the personal pronoun he refers specifically to the antecedent noun dog), but to a more general or, as their title has it, indefinite referent (as in some of the dogs were barking because they were hungry, where the indefinite pronoun some is referring nonspecifically to the generality of dogs in question). This all seems fairly straightforward, and few writers would be tempted to change the number of the verb in either example.
Nor is it likely that we would change the verb in this example: Some of these angry dogs are fit to be tied because some of this food is rotten. Why is the verb plural (are) in the first clause but singular (is) in the second? Notice in these examples that between the indefinite pronouns and their respective verbs lies a prepositional phrase (of these angry dogs and of this food). Prepositions make up another one of the eight parts of speech, and they always require an object of some sort (usually a noun or pronoun), the resulting group of words being called a prepositional phrase. The sign we are to watch for, then, is whether the object of the preposition is singular or plural: if the prepositional phrase between an indefinite pronoun and its verb is singular, then the verb is singular (some of this food is); conversely, if the prepositional phrase between an indefinite pronoun and its verb is plural, then the verb is plural (some of these angry dogs are).
This rule of the grammatical road applies to many (but not all) of the indefinite pronouns. All is another indefinite susceptible to this standard guidance, but here we can get a glimpse into why there is such a rule at all. In the sentence all of these cats are sleeping, so all is finally quiet for a while, the first clause poses no problem, because the object of the preposition, cats, is plural, and so the verb, are, is plural. Same rule, same application. But why is the verb of the second clause, is, singular? This instance of the indefinite all is really indefinite, because its antecedent is not one of the unnamed cats, but the entirety of the general situation or circumstance created now (and no doubt thankfully) by the fact that the cats are finally sleeping. The writer is, reasonably enough, expecting readers to read between the lines (that is to say, read closely and insightfully) and supply what can be justifiably assumed to be the meaning intended.
But let’s fly the guardrails and see what happens. If we change the singular is of that second clause to the plural are, the intended meaning is overturned: the indefinite pronoun all in all are finally quiet for a while now refers back to the cats once again, and although that is a logically possible set of affairs, it is a meaning at variance with what the writer had originally wanted to say. A quiet house is one thing, quiet cats quite another. This omission of what is otherwise logically necessary is called ellipsis, a rhetorical figure of speech that is everywhere in English, particularly in diction more casual than formal, that is, occasions where it is reasonable and not self-inflicting to trust the reader with finishing your thought.
Likewise, caution is in order with the pronouns any and none. Both of these begin by following the same rule governing the number of the prepositional object. The verb (are) is plural in any of the dogs in this room are adoptable because the object dogs is plural; and the verb (is) is singular in any of this food is suitable for your dog because the prepositional object food is singular. But if the indefinite any means any one (even if followed by a plural prepositional object), then the verb remains singular: any of the dogs in this room is adoptable, thereby emphasizing the number of singular possibilities (any one of) to choose among. So too with none. When none means no, the verb will be plural: none of the cats in this room are particularly friendly means no cats in this room are particularly friendly. But if none means not one (again particularizing the referent), the verb will be singular: None of these cats is friendly means not one of them is.
As is so often the case, this grammatical guardrail is meant to keep us precise—in thought and in the style in which we express the thought. In both grammar and thinking, the point is to avoid being arbitrary, to possess ourselves from wandering off into the vague and suggestive. These insinuating qualities deceive rather than enlighten, but they can be guarded against by keeping to the ways of the craft.
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