A "to be" verb is a verb that shows a state of being, not an action. This means it describes the existence, condition, or state of someone or something rather than an action they are performing.
For example:
- The flowers are beautiful. ("are" is the "to be" verb describing the state of the flowers)
- She is happy. ("is" is the "to be" verb describing her state of being)
- They were tired. ("were" is the "to be" verb indicating their state at a particular time in the past)
So, the correct answer is D. a verb that shows a state of being, not an action.