Final answer:
The sentence provided contains one collective noun, which is 'class.' The collective noun refers to the group as a single entity and will usually be followed by a singular verb in this context.
Step-by-step explanation:
A collective noun is a word referring to a collection of things taken as a whole. Most collective nouns in everyday speech are not specific to one kind of thing. For example, the collective noun "group" can be applied to people, or dogs, or objects.
In the sentence "When I was in second grade, I loved my teacher and class. We were," there is one collective noun. The collective noun in this sentence is 'class.' Collective nouns refer to a group of individuals or things as a single entity.
An example of collective nouns being used correctly could be: "The class was excited about the field trip." Depending on the context, a collective noun can take a singular or plural verb. In this case, 'class' is being used to refer to the group as a single unit, which would normally be followed by a singular verb, such as 'was' or 'is.'