As shown in the examples below, when writers craft sentences with more than one noun or pronoun in the subject, they sometimes misidentify the key noun or pronoun and assign the wrong verb form to it. Discussion and revision in each sentence describes and solves the problem.
1. “Five days are too short for a vacation.”
The singular form of the verb “to be,” rather than the plural form, is appropriate here because of the context—the writer is referring to a collective unit of time consisting of five days, not to five units of time consisting of a day each: “Five days is too short for a vacation.”
2. Which of the following statements best describe your situation?
The verb in this sentence refers not to statements but to one of several statements—represented by the pronoun which—each of which is, in turn, being contemplated on its own, so the verb form should be singular: “Which of the following statements best describes your situation?”
3. Each of the top five priorities identified this year are technology related.
Just as in the previous example, the first word in this sentence is a place-holder representing one priority. The five priorities are being considered in isolation, one at a time, so a singular verb is appropriate: “Each of the top five priorities identified this year is technology related.”
4. We believe that a diversity among people and perspectives create high-performing organizations.
Diversity, not the combination of “people and perspectives,” is the operative noun here, so the verb form should be singular: “We believe that a diversity among people and perspectives creates high-performing organizations.”
5. A combination of these factors, along with a number of wider digital transformation and economic trends, have focused attention on regulatory technology as a topic.
Combination, not factors, is the noun that the helping verb is associated with (and the parenthetical phrase located between factors and the verb is irrelevant to the verb form): “A combination of these factors, along with a number of wider digital transformation and economic trends, has focused attention on regulatory technology as a topic.”
Some people may disagree, arguing that combination, like descriptive words such as couple, majority, and variety, calls for notional agreement (or notional concord), in which plural nouns that modifying phrases that include collective nouns are associated with, rather than the collective nouns themselves, are considered the “target” of the verb. However, usage strongly favors singular concord, in which the verb concords, or agrees, with the collective noun (the “notion”).