The verb is always an action verb . Another way of saying it is that the subject does the verb to the direct object. To find the direct object , say the subject and verb followed by whom or what. Tree answers the question so tree is the direct object. If nothing answers the question whom or what , you know that there is no direct object.
Nothing answers the question so the sentence has no direct object .
The direct object must be a noun or pronoun. A direct object will never be in a prepositional phrase. Find the subjects, verbs, predicate nominatives, and direct objects in these sentences. Mutt and Jeff were old comic characters. Ila scraped and rubbed the old tub for hours.