Which form does a verb take when the subject performs the action? active passive imperative indicative

The form that a verb takes when the subject performs the action is the active form. For example - Mary is reading a book. The verb reading is active, because Mary is doing some kind of an activity. Passive verbs are used in passive sentences, such as - That book was written by him. Imperative sentences give some sort of a command, and indicative refers to stating facts.