How to teach Z to your child will depend on the errors that your child is making.
If you have been working on S, Z is VERY similar. The only difference is voicing. If this is your child, you have it easy!
If your child has a frontal lisp, you need to teach your child to move their tongue back.
1. Have your child say “eee.” The act of saying “eee” naturally brings the tongue back. Tell your child to feel how the sides of the tongue touch the back molars. This is where the tongue should always be when we say Z!
Once that has been mastered, move on to saying N.
2. Have your child say “teen.” When your child says “teen,” make sure the tongue is behind the teeth and the jaw is up/stable (not moving forward, down, or side to side). Refer back to how to say S for a refresher course on tongue placement if needed!
Practice here with different cues to either remind your child to keep their tongue behind their teeth, jaw stable, etc…
3. Have your child say “teens.” This is the easiest position as your child’s tongue is already back and not sticking out between the teeth (with “eeee”) and the tongue tip is behind the teeth (with T and N). Now, we just add Z. Stay here for a few or many practices…as long or as short as it takes. Frequently, children’s tongues will move forward when Z is added to "teen." An insider tip is to have your child say “teen” and then say, “keep your tongue light and frozen when you add Z.”
Using a mirror at this point is also helpful.
4. Say silent "teen" with a loud Z. Once your child can say "teens," ask him or her to say "teen" silently but say the Z out loud. If your child can do it, give praise for saying Z correctly! If this is too abstract, skip it!
5. Practice Z solo: Have your child say Z using all the techniques just reviewed. If your child can do it, move to the syllable level for more practice. If not, keep practicing here for a few more rounds.
If your child has a lateral lisp, you need to teach your child to move the edges of their tongue up and rest firmly on their molars as well as the air to move out the front of the mouth.
Correcting a lateral lisp is difficult because your child cannot see his or her errors. Instead, your child has to hear and feel for correct and incorrect pronunciations.
Correcting Lateral Lisp:
1. Get sides of the tongue up (to prevent air from escaping from the sides of tongue)
Say “zsh" as in "measure" and have your child feel how the sides of the tongue are squished up and against the molars. Have your child feel how the air comes out the front of the tongue.
2. Air out the front
While your child says “zsh,” have your child transition slowly to Z, i.e.,”zzzzshhhhhzzzzz.”
If your child is successful at this level, keep practicing ”zzzzshhhhhzzzzz” while slowly decreasing the “zsh” while prolonging Z. Soon, your child should be able to say Z by himself or herself correctly.
Once this is mastered, transition to the syllable level for more practice.
REMEMBER: Watch the jaw. Make sure it is: