Singular goes with singular, plural with plural. Sounds easy. Yet agreement problems abound in our prose, between subjects and verbs, between nouns and pronouns. The perils are all familiar: phrases intervening between subject and verb that throw us off track; collective nouns that veer from singular to plural; tricky words like “each”; and, of course, that infamous “one of the people who …” construction that we simply refuse to get right.

After Deadline http://afterdeadline.blogs.nytimes.com/2013/09/10/ugly-disagreements/