No, not just the vowels, a, e, i, o, u and y. That doesn’t really help. But the vowel sounds. ai, au, ou, oa, ea, ee and so forth.
So here is a little thing that you could do to help your child become a better reader. Before you have them start reading, go through the words pointing to the vowels and have them tell you what sound each vowel sound makes.
Here is an example.
“When the rain started falling, it fell fast and hard.”
So you would point to each of the vowel sounds and your child would say the sound. Then go back and read. Don’t make them sound out the vowel sounds too much. You should know about how long they can take it. 30 seconds to a minute should be plenty.
I have seen some improvement here at home with this.