Using different voices while you read emphasizes that stories have different characters.
Toddlers and preschoolers love to hear you read stories! Pick out a book with different characters, and read it using different voices for each character. This will really call your child's attention to the fact that there are different characters in the story.
After a character speaks, ask your child, "Who said that?" Of course, he may answer that you said it! But try to have your child point to which character from the story is talking.
Knowing and differentiating story characters helps children engage with stories. As they grow and become readers themselves, they will be able to understand what they read and learn about perspective taking.