Collective nouns can be taken as singular or plural, according to whether the word is seen as a unit or as individual items.
For example:
Thefamilyis proud ofitslineage.
Family is seen as a whole unit and so takes singular verb and pronoun.
Thefamily weredivided intheiropinions.
Members have different views and so the collective noun family cannot be perceived as a whole; so it takes a plural.
Nature of the word
Every afternoon the baseballteam follows itscoach to the playground.
The members of the team follow the same practice and so it takes a singular verb and pronoun.
After the practice session theteamheads towardstheirrespective rooms.
The team mates are heading to their individual rooms and so the noun is treated as plural.
When the members of collective behave in a similar fashion, the noun is singular and takes singular verbs and pronouns.
When the members act as individuals, the collective noun is plural and requires plural verb and pronoun.
