CVC SHORT Oo Sound.
Vowels are very important in reading as they give volume and depth to words. This 5-in-1 pack of booklets introduces the basic vowels to early readers ie, a, e, i, o, u. Each one of the five booklets focuses on one vowel sound together with consonants to make a meaningful 3 letter word. Eg. With the vowel a we have words like m-a-t, c-a-p, and so on. Your child is most likely to be able to read/sound most if not all simple words with short sounds.
This resource is terrific for your 3-4 year olds.