A verb is a word or phrase that indicates action or existence. An action can be described as occurring in the past, present, or future.
Present Past Future I am. I was. I will be. He thinks it over. He thought it over. He will think it over. You go to the bank. You went to the bank. You will go to the bank.
A verb may be the entire predicate (I am) or part of the predicate (He thinks it over).
A verb that performs its action on an object is transitive.
She ate her sandwich.
They furnish the room.
A verb that does not take an object is intransitive.
The badger eats.
Some verbs can be either transitive (She ate her sandwich) or intransitive (She ate). Other verbs are usually transitive or usually intransitive.
A verb can be in either the active or the passive voice, depending on whether its subject does the action of the verb or is acted on. The following examples show verbs in the active voice:
A surgeon operates.
The sculptor shapes clay.
We received an e-mail.
In the second example, sculptor is the subject of the sentence and performs the action of the verb shapes. Notice how the form of this verb changes when it is in the passive voice:
The clay is shaped by the sculptor.
Sculptor is still the subject but is now being acted on by the verb. When a verb is in the passive voice, the subject may sometimes be dropped from the sentence:
The clay is shaped.
My apple was eaten.
In such cases, the subject can often be inferred from context (e.g., a discussion of the sculptor’s work), or the sentence may express uncertainty (e.g., about who ate the apple).