Blending is the process of saying the individual sounds in a word the running them together to make the word. For instance sounding out d-o-g and making dog. It is a technique every child will need to learn, and it improves with practice. To start with you should sound out the word and see if a child can hear it, giving the answer if necessary. Some children take longer than others to hear this. The sounds must be said quickly to hear the word. It is easier if the first sound is said slightly louder. Try little and often with words like b-u-s, t-o-p, c-a-t and h-e-n. There are lists of suitable words in The Phonics Handbook and the Jolly Phonics Word Book.
Remember that some sounds (digraphs) are represented by two letters, such as sh. Children should sound out the digraph (sh), not the individual letters (s-h). With practice they will be able to blend the digraph as one sound in a word. So, a word like rain should be sounded as r-a-i-n, and feet as f-e-e-t. This is difficult to begin with and takes practice. The Jolly Phonics Regular Word Blending Cards can be used in class to improve this skill.
You will find it helpful to be able to distinguish between a blend (such as st) and a digraph (such as sh). In a blend the two sounds, s and t can each be heard. In a digraph this is not so. Compare mishap (where both the s and h are sounded) and midship (which has the quite separate sh sound). When sounding out a blend, encourage children to say the two sounds as one unit, so fl-a-g not f-l-a-g. This will lead to greater fluency when reading.
Some words in English have an irregular spelling and cannot be read by blending, such as said, was and one. Unfortunately, many of these are common words. The irregular parts have to be remembered. These are called the “tricky words”.