|6. Direct Object and Indirect Object|
As mentioned, a sentence has to be clear in its meaning. If I say "I saw", my meaning is not clear to you. You may want to know what I saw. When I say, "I saw a ghost", I named the thing or object that I saw, and my meaning becomes clear. The word "ghost" is the Direct Object of the verb "saw." The object is the part of the sentence that undergoes the action of the verb, which in this case is saw. The direct object generally comes after the verb. (The verb saw is called a Transitive Verb. A transitive verb needs an object to complete a sentence and make its meaning clear.)
EXAMPLE: The dog barks. (subject: dog; verb: barks. No object present.)
EXAMPLE: A cat catches mice.
EXAMPLE: His train departed at ten o'clock. (No object.)
EXAMPLE: He bought her a puppy. (A sentence that contains two/both objects.)