What are words that a part of the verb to be?

The words that are part of the verb "to be" are called be verbs or linking verbs. They are:

* am

* is

* are

* was

* were

* been

* being

These words connect the subject of a sentence to a predicate nominative or predicate adjective, which describes or identifies the subject.

Examples:

* I am tired. (am links the subject "I" to the predicate adjective "tired")

* She is a doctor. (is links the subject "She" to the predicate nominative "doctor")

* They were happy. (were links the subject "They" to the predicate adjective "happy")

It's important to note that "to be" can also be used as part of a verb phrase, such as "going to be" or "should have been." In these cases, the verb phrase acts as a single unit.