English Grammar: Agreement of Pronouns

Agreement — Pronoun with a Compound Antecedent

Sometimes the pronoun refers to two antecedents connected by and. If both of these antecedents are singular and refer to different persons or things, the antecedent is plural. The pronoun that refers to these antecedents must also be plural.

The president and the manager have outlined their plans.

If the antecedent refers to one person who fulfills two functions, the pronoun that takes the place of the antecedent is singular. In the following sentence cook and housekeeper are the same person.

The cook and housekeeper did not like her duties.

If the housekeeper were another individual, the word the would be placed before the word housekeeper.

The cook and the housekeeper did not like their duties.

When the connectives, either — or and neither — nor join singular nouns, the antecedent is singular. When they join plural nouns, the antecedent is plural. When they join nouns that differ in number, the pronoun should agree with the antecedent that is nearer to it.

Either Jane or Alice left her book on her desk.
(Both nouns are singular — pronoun is singular)

Either the boys or the girls left their books on the table.
(Both nouns are plural — pronoun is plural)

Neither Harvey nor his cousins wore their hats.
(Pronoun is plural — agrees with cousins)

Neither the men nor the boy could find his place in the line.
(Pronoun agrees with boy which is nearer to it.)

In sentences like the last one, it is better to place the plural noun nearer to the pronoun. By doing so, you make the antecedent plural, and the sentence sounds better.