NG Style Manual‎ > ‎- C -‎ > ‎


Collective nouns, or collectives (family, team, couple, etc.), tend to be plural when the component members are considered separately and singular when the group is handled as a unit:
            a score were present
            an army marches on its stomach

The plural often prevails when humans are concerned:
            The couple are. . . .

The decision between singular and plural is frequently writer's choice.   Once the number is established, be consistent:
            My family trusts only people it knows
            my family trust only people they know
            Dr. Smith's team works long hours in the hot sun,
                        but it [not they] always maintains an esprit de corps.
             Piersma's team works fast; the scientists [not they] prepare
                        a net to be fired by mortars
            The enemy wasn't interested merely in conquest; it [not they] wanted
                        to wipe Aguateca off the map.

Generally speaking, a number, a fraction, or a quantity of things is singular if considered as a mass (ten gallons is enough) and plural if considered as separate units (ten dishfuls were slowly doled out).

Generally use a plural verb when human beings are implied:
            Half the wine is enjoyed ...
            Half of these people are engaged ...
            35 percent of the bread goes ...
            35 percent of the grapes go ...