Here's why:
* Linking Verbs: Connect the subject of a sentence to a noun, pronoun, or adjective that renames or describes the subject.
* "Should have been" functions as a past perfect conditional, indicating a past possibility or necessity.
For example:
* "He should have been more careful." In this sentence, "should have been" links the subject "he" to the adjective "careful," describing his state.
Let me know if you have any other grammar questions!