One of the first requirements of a good, solid sentence in English is what is known as subject-verb agreement. Sentences are made up of clauses, clauses of subjects and verbs, and the subject of a clause can be either singular or plural. Right there is what the concept of subject-verb agreement points to, because the number of the verb must agree with the number of the subject.
Now before you conclude that this is so elementary a topic that little more needs to be said about it, I will remind you that just what constitutes a subject is not always easy to answer. It’s true that the concept is basic in the study of grammar, but basic mistakes still occur. Just the other day I saw this question in a search online: Are there a shortage of doctors in the United States? The writer apparently thought that the plural noun doctors was the subject of the clause, and so assigned the plural verb are to it. But doctors is the object of the preposition of, not the subject. The singular noun shortage is the subject, and so the verb should be the singular is: Is there a shortage of doctors in the United States? (The answer, apparently, is yes, and growing more serious.)
Now what makes this topic tricky is that with certain words, among them the indefinite pronouns none and any, the verb can be either singular or plural, depending upon the shade of meaning we intend to depict. Take this sentence, for example: None of these hospitals have the facilities to treat the disease properly. The pronoun none is the subject of the sentence, working with the plural verb have. The fact that hospitals is plural and happens to be positioned right next to the verb have is coincidental, not determinative; the plural noun hospitals is the object of the preposition of (parallel to the earlier example above), and does not figure in finding the number of the verb at all.
But it is possible in good standard English to write this sentence: None of these hospitals has the facilities to treat the disease properly. Now the same pronoun none has been assigned a singular verb, has. So what’s the difference? When we intend the pronoun none to mean not one, the subject is singular: None of these hospitals is means Not one of these hospitals is. Constructing the sentence like this puts the reader’s attention on each particular hospital that has been referred to in the discussion, and that may be the better stylistic choice to emphasize the fact that the lack of technology or expertise is not only widespread, but something individual administrations of certain independent hospitals are confronting.
When the same pronoun none, however, means no, then the subject is plural: None of these hospitals are means no hospitals are. In this construction, the reader’s attention is being directed to a group of hospitals sharing a common characteristic (the absence of a certain technology or expertise), not to any one individual member of the group. The statement is more sweeping, more panoramic, as if the writer were moving a finger across a region on a map to illustrate where the lack exists. The plural none points to a general condition, while the singular none suggests a particular site where that condition is present.
And the very same thinking is involved in choosing a singular or plural verb for the pronoun any. To write Any of the hospitals in this region has the technology to help you means any one hospital, so make your choice of hospital on another criterion. But assign a plural verb to the same pronoun and the intimation changes: Any of the hospitals in this region have the technology to help you means All the hospitals, so you’re in the right general place in the world with a lot of resources everywhere to help you.
The fact that we can change the connotation, or suggestion, or certain words by changing the number of the verb is the real lesson here, because our natural logic (as opposed, perhaps, to a mathematical language) is more roughly cut than we think. We know the thought we’re writing, and we forget that our audience must be brought into the world of which that thought is a part, an environment of associated ideas all its own. We can point to that background in many different technical ways, one of which, sometimes and carefully, is subject-verb agreement.
***