Most people think that since collective nouns refer to groups of people/things that they should always be treated as plural nouns. That is not the case. Collective nouns, such as navy, jury, and council, can be treated as singular nouns in certain circumstances. The only way for a writer to decide whether or not to treat a collective noun as a plural or singular noun is to analyze the context of the whole sentence.
If the sentence describes the activity of a group of people acting in unison, then the collective nouns should be treated as a singular noun. However, if the sentence describes a group of people who are not doing the same thing at the same time, then the collective noun should be treated as a plural case.
An example to better illustrate the first point is the sentence, “the class takes the test in Mr. Olaf’s classroom.” In this example, “class” is the collective noun that is treated as a singular noun. Since the class is taking the test all at the same time, we can consider this a singular entity. The class members are doing one activity at one time in one place together.
Now let’s look at this sentence, “the class start their art projects.” The collective noun “class” is interpreted as a plural noun here because the class members are going to do their art projects separately in different places at different times. In other words, the students in the class are working independently, not as a single group.
Sometimes it can be hard for a writer to know whether or not a collective noun is plural or singular. There are a few tricks to help writers out with this conundrum. The simplest solution is to add the word “members” behind a collective noun. This will instantly make it plural.