First, what’s a collective noun?
A collective noun refers to “a whole group as a single entity” but also to the members of that group. A collective noun names “a group of individuals or things with a singular form.”
So, do I use a singular or plural verb with a collective noun?
Generally, in American English, collective nouns take singular verbs. In British English, collective nouns are more often treated as plurals that take plural verbs.
However, the use of a singular or plural verb can depend on the context of the sentence.
If you are referring to the whole group as a single entity, then the singular verb is best.
For example, “the school board has called a special session,” or “the faculty eats the donuts.” When a group noun is used with a singular determiner (e.g., a/an, each, every, this, that), singular verbs and pronouns are normal, like in this sentence: “The team is away this weekend; they have a good chance of winning.”
There are other contexts where the plural verb is more natural: My family are always fighting among themselves. When the individuals in the collection or group receive the emphasis, the plural verb is acceptable.