Determine if the speech errors causing difficulty in being understood is an age-appropriate speech error. For instance, by age 4, a child should no longer have difficulty pronouncing these sounds: p, b, m, h, w, d, n, k, g, t, ng and f. A preschooler who has trouble pronouncing y, l, s, sh, ch, z, j, v and r may just need more time and will most likely develop the skills by age 7 or 8.
Model how to say the sounds correctly to the preschooler. For instance, for the sound k, the rear of the tongue is raised to touch the soft palate and air pressure builds behind the point where the contact is made and then is released when the tongue is lowered and the contact broken.
Work on sounds the child has difficult with by taking a sound walk. Take a walk through the neighborhood, looking for things that begin with the target sound. Give the preschooler a small treat, a candy or sticker, for instance, for each thing found that begins with the target sound. Again, model the sound correctly --- over enunciating the target sound for the child.
Cut out pictures of objects that begin with the sounds the preschooler has difficulty pronouncing and paste these pictures onto index cards. Make sure there are two pictures of each sound. Play a memory game with the pictures by shuffling the cards and placing face down. Take turns turning over two cards; if they match, the player takes the cards and places them in a pile in front of the player. The player with the most matches at the end of the game, when all the matches have been uncovered, wins. Make certain to say the words as each card is turned over during the game and ask the child to repeat after you.
Take the picture cards from Step 4 and play the mailbox game. In this game, you will hand a picture card to the preschooler. If the child pronounces and names the picture correctly, they may mail the card. The child will mail the card into a shoebox decorated to resemble a mailbox complete with a slot cut out for mailing the picture cards. If the child does not pronounce the word correctly, the card is sounded out correctly by you, then put back into your pile.
Create a collage of pictures of objects that begin with the target sound you are working on with the preschooler. Let him draw pictures, cut out pictures from magazines, cards or coloring books. Paste the images onto a piece of colored construction paper.