Transitive verbs take at least one object. A simple sentence containing a transitive verb might read, "I threw the ball." The ball is the direct object, and "threw" is a transitive verb. Intransitive verbs, on the other hand, don't require a direct object. If you say, "I slept," this demonstrates an intransitive verb, since there is no object in the sentence. Even if you were to say "I slept on the couch," the verb remains intransitive because the couch is an indirect object.
Since verbs describe actions, you can have the students learn about transitive verbs using a game. Bring a ball to class. Have the students pass the ball around, and as they do, explain that the ball would be a direct object because it is being passed around the room. Tell them that in this activity, the word "pass" is a transitive verb, since each of the students can say, "I passed the ball to the next student."
Give each student a piece of paper and some colored pencils. Have them draw or write and explain that their drawings are direct objects, while the paper is an indirect object: in the sentence, "I drew a man on the paper," the verb is still transitive, because it has a direct object. Ask the students if the verb is still transitive if the sentence were, "I drew on the paper." This is a tough question, since an object seems to be implied, but the verb is intransitive in this sentence.
For younger students, you can modify a familiar game to teach about transitive verbs. Have students line up as they would in a game like Simon Says, but tell them that they should only listen to commands with transitive verbs. Some commands could be, "touch your head," "wave your hands" or "take a step," while some commands with intransitive verbs would be, "turn around," "hop on one foot" or "laugh out loud."