Every sentence has a verb, which means that a sentence isn't complete without one. There are three types of verbs.
1. Action verbs: These verbs state what the subject of the sentence is doing. Run, jump, compile, and learn are examples of action verbs.
2. To be: The verb to be (conjugated as am, is, are, was, were, been, and being) functions sort of like an equal sign. It equates the subject with a noun or adjective. For example: Ben is successful means Ben = successful. She is a CEO means she = CEO.
3. Linking verbs: These words join (or link) the subject to an adjective that describes the condition of the subject. Like the verb to be, they express a state of the subject, but they provide more information about the subject than to be verbs do. Common linking verbs are feel, seem, appear, remain, look, taste, and smell.
Tense of a verb describes the time of an action or of an event. There are three universal times - present, past and future. Tenses cover the actions done in these times. The Tense also refers to the continuation or completion of an action. However, everything is implied in the three time periods.
Verbs express actions and have three basic types of tenses:
Each of the three tenses has four forms that indicate the nature of the action described by the verb.