Present tense could be used when relating direct speech, or the immediate intentions of the characters, as in the following example: Tom hurried down the pathway, looking over his shoulder. "Come with me!" he shouted.
If you can just silence the left brain (by that I mean the logical side) long enough for the kid to hear a story every day in the past tense, he will get a feeling for when to use which tense.
Continue speaking (telling the story, asking questions about it, or talking about it) in the past.