A child can understand words read aloud more easily than words in a book. A parent’s voice adds tone, cadence, volume, and other non-verbal markers of meaning, elements a child has to create on his own when he reads. This means that a child can understand a more advanced book with more sophisticated words and ideas if he hears it. Reading it by himself would be too stiff a challenge.
Everybody knows how important it is to read to toddlers. Apart from the emotional element, reading out loud every day during the pre-K years sends a child to kindergarten with a significantly larger vocabulary than a child without that experience possesses. And what happens in kindergarten and after is that the gap grows (because of what is called the “Matthew Effect”).
But many parents make the mistake of discontinuing reading when their children learn to read on their own, around ages 6–8. This is a mistake, for two reasons.
One, the emotional reason.
And two, the intellectual reason.