Write uppercase and lowercase "Ds" on a large board or hold up copies of them. Keep this aid clearly viewable while doing these activities, since you want the children to be able to connect the sound with the letter.
Practice making the D ("duh") sound aloud with your preschooler(s). Say "This is the letter 'dee' and it makes the 'duh' sound." Point out how the tongue touches the front roof of the mouth when making the sound.
Repeat "duh, duh, duh" a few times and let them make the sound quietly and loudly, quickly and slowly. Making silly sounds is a good way for preschoolers to learn.
Add words to the "duh" sounds as you say them out loud, emphasizing the beginning sound ("Duh-duh-dog," "Duh-duh-door"). Let the children pick some "D" words, too.
Point out objects in the room or people's names that begin with "D." Say the words or names clearly, emphasizing the "D" sound, and have the children repeat the words.
Say words that end in "D" and emphasize the difference between a beginning and ending sound.
Read alphabet books and picture word books with your preschoolers. Say the words aloud and ask the children to point at pictures that have a "D" sound.
Use worksheets and coloring pages to identify objects that begin with the "D" sound. Circle or color the "D" words.
Play a quick Letter Hunt game. Set a timer for a minute or two and have your preschoolers find as many "D" objects in the room before the timer rings. Reward them with stickers for each correct object.
Suggest that parents ask their children to find the letter "D" on a cereal box, in a store, or on signs while they're in the car.
Use flashcards to help preschoolers recognize both the name of the letter and the letter sound.
Play letter identification games online if you have access to a computer in your room. Several children's and educational sites have games geared to preschoolers.
Draw lines and squiggles, including pictures that look like the shapes used in letters. Drawing helps children learn to be comfortable making the squiggles and marks we put together for letters. The skill also helps develop the hand-eye coordination needed for writing. For the letter "D," children may practice lines, bumps and circles.
Show your preschoolers how to write the letter. Slowly write each part in clear handwriting. For a capital "D," begin at the top of the line and make a straight bar down. Then make the round bump from top to bottom. For a lowercase "d," start the bar at the top also, and make the round arc halfway down the left side of the bar. Point out that the bump is on the left side or "back " of the bar, so it's not confused with a "b."
Have your preschoolers practice writing both the capital "D" and lowercase "d" on lined paper.
Let children write silly words or small sight words (i.e., "do," "dad"). Don't emphasize spelling at this point. Stringing letters together teaches children how to write them, which comes before reading and spelling.
Start a letter book. In a notebook, let children write, draw and paste cut-out pictures that represent the letter "D." Each page can be dedicated to a new letter until alphabet books have been created.