One of those things
Yesterday on Twitter, @DailyEngHelp and @EditorMark were tossing this sentence back and forth:
Mary Smith is one of the librarians who oppose(s)? the contract.
I thought I’d bring this to a wider audience, because determining whether the verb in the subordinate clause should be singular or plural is a point in which writers often get entangled.
The matter to settle is whether the pronoun who is a singular or plural. Many writers wrongly assume that it must refer back to Mary or maybe one, since one is identical to Mary, and must therefore be singular. But the nearer antecedent is librarians, and it cannot be ignored.
There are two ways to talk about Mary in this context. The first would be to emphasize her individual status: Mary is one who opposes the contract. The antecedent of who is one.
But if the intent is to identify Mary as part of a discrete group, then: Mary is one of the librarians who oppose the contract.