Collective nouns—such as family, team, audience, group, jury, crowd, band, class, and committee—refer to a group. Collective nouns can take either singular or plural verbs, depending on whether they refer to the group as a single unit or to the multiple members of the group. The meaning of a sentence as a whole is your guide to whether a collective noun refers to a unit or to the multiple parts of a unit.

The jury acts as a single unit.

The members of the jury act as multiple individuals.

Family here refers to the many ducks; they cannot scatter as one.

Treat fractions that refer to singular nouns as singular and those that refer to plural nouns as plural.

Two-thirds of the park has burned.

Two-thirds refers to the single portion of the park that burned.

Two-thirds of the students were commuters.

Two-thirds here refers to the students who commuted as many individuals.

Even though eyeglasses, scissors, pants, and other such words refer to single items, they take plural verbs because they are made up of pairs.

Where are my reading glasses?

Treat phrases starting with the number of as singular and with a number of as plural.