Speech & Communication

Toddler Puts Tongue Between Teeth for S Sound

Medically reviewed by Dr. Emily Torres, PhD, CCC-SLP · Pediatric Speech-Language Pathologist

Content reviewed against published ASHA, AAP, NIH guidelines

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Speech and communication milestones vary widely, and worries about toddler puts tongue between teeth for s sound, here is what you need to know.

The short answer

An interdental or frontal lisp, where the tongue slides between the teeth during S and Z sounds (making them sound like TH), is a common developmental pattern in young children. Most children outgrow this by age 4.5. If the lisp persists past this age, speech therapy can help your child learn correct tongue placement.

Key takeaways

  • An interdental or frontal lisp, where the tongue slides between the teeth during S and Z sounds (making them sound like TH), is a common developmental pattern in young children. Most children outgrow this by age 4.5. If the lisp persists past this age, speech therapy can help your child learn correct tongue placement.
  • Usually normal when: Your child is under 4.5 years and places their tongue between their teeth for S and Z sounds
  • Call your doctor if: Your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes
  • Varies by age — see the age-by-age breakdown below

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What Parents Should Know

According to ASHA, AAP, NIH guidelines, an interdental or frontal lisp, where the tongue slides between the teeth during S and Z sounds (making them sound like TH), is a common developmental pattern in young children. Most children outgrow this by age 4.5. If the lisp persists past this age, speech therapy can help your child learn correct tongue placement. At 18-24 months, s sounds are just beginning to develop. Lisping is not a concern at this age as children are still learning how to position their tongue for different sounds. Many toddlers do not yet produce S sounds at all. It is generally considered normal when your child is under 4.5 years and places their tongue between their teeth for S and Z sounds. However, you should contact your pediatrician promptly if your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes.

Sources: [1], [2], [3]

Normal vs. Concerning

Usually Normal
Worth Discussing
Your child is under 4.5 years and places their tongue between their teeth for S and Z sounds
Your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes
Your child's lisp is consistent, not something that appeared suddenly
Your child is over 5 years and the lisp is affecting their confidence or willingness to speak
Your child's other speech development is on track aside from the lisp
Your child is over 4.5 years and still has a consistent frontal lisp
Your child is not frustrated or self-conscious about their speech
Your child's lisp is accompanied by other speech sound errors

By Age

What to expect by age

18-24 months

S sounds are just beginning to develop. Lisping is not a concern at this age as children are still learning how to position their tongue for different sounds. Many toddlers do not yet produce S sounds at all.

24-36 months

An interdental lisp is very common and completely normal during this period. Many children naturally place their tongue between their teeth when attempting S and Z. This usually resolves as oral motor control improves.

3-4 years

A frontal lisp is still considered normal at this age. Many preschoolers lisp and most will outgrow it. Correct S production typically emerges between ages 3.5 and 4.5. No intervention is usually needed yet.

4-5 years

By age 4.5, the frontal lisp should be resolving. If it persists, speech therapy may be recommended. Some speech-language pathologists prefer to wait until age 5 before beginning treatment, as many children self-correct during this period.

5-7 years

A frontal lisp that persists past age 5 is unlikely to resolve on its own and speech therapy is recommended. Treatment is typically effective and straightforward, teaching the child to keep their tongue behind their teeth.

What to Tell Your Pediatrician

  • Describe when you first noticed toddler puts tongue between teeth for s sound and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if your child is over 4.5 years and still has a consistent frontal lisp.
  • Mention if your child's lisp is accompanied by other speech sound errors.
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

What Should You Do?

When to take action

Probably normal when...
  • Your child is under 4.5 years and places their tongue between their teeth for S and Z sounds
  • Your child's lisp is consistent, not something that appeared suddenly
  • Your child's other speech development is on track aside from the lisp
  • Your child is not frustrated or self-conscious about their speech
Mention at your next visit when...
  • Your child is over 4.5 years and still has a consistent frontal lisp
  • Your child's lisp is accompanied by other speech sound errors
  • Your child is starting school and is self-conscious about lisping
Act now when...
  • Your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes
  • Your child is over 5 years and the lisp is affecting their confidence or willingness to speak

What You Can Do at Home

  • Keep track of when you notice toddler puts tongue between teeth for s sound — noting the time of day, duration, and any triggers can help your pediatrician.
  • Remember that your child is under 4.5 years and places their tongue between their teeth for S and Z sounds — this is generally within the range of normal.
  • At 18-24 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
  • Talk, read, and sing to your baby frequently. Narrate daily activities to build language exposure.
  • While monitoring at home, seek immediate care if your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes.

My Toddler Has a Lisp

Lisps are very common in toddlers and preschoolers who are still learning to make certain sounds. Most children don't master the "s" sound until around age 4-5, so a lisp before then is usually developmentally normal. If your child still has a noticeable lisp after age 5, or if it's affecting their confidence, a speech evaluation can help.

Toddler Has a Slushy S Sound (Lateral Lisp)

A lateral lisp produces a "slushy" or wet-sounding S and Z, caused by air escaping over the sides of the tongue rather than through the center. Unlike a frontal lisp (tongue between the teeth), a lateral lisp is not considered a normal developmental pattern and typically requires speech therapy to correct. If you notice this sound quality in your child, a speech-language evaluation is recommended.

Child Cannot Say the S Sound

The S sound is typically mastered between ages 3 and 5. Many young children substitute TH or T for S, which is normal developmental variation. A frontal lisp with S is common and often resolves by age 4.5. If S errors persist past age 5, or if your child has a lateral (slushy) lisp, a speech evaluation is recommended.

Milestone

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Guide

When to Call the Doctor

General guide on when to call the pediatrician, visit urgent care, or go to the ER.

Frequently asked questions

Is toddler puts tongue between teeth for s sound normal?
An interdental or frontal lisp, where the tongue slides between the teeth during S and Z sounds (making them sound like TH), is a common developmental pattern in young children. Most children outgrow this by age 4.5. If the lisp persists past this age, speech therapy can help your child learn correct tongue placement.
When should I call the doctor about toddler puts tongue between teeth for s sound?
Your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes Your child is over 5 years and the lisp is affecting their confidence or willingness to speak
When is toddler puts tongue between teeth for s sound normal?
Your child is under 4.5 years and places their tongue between their teeth for S and Z sounds Your child's lisp is consistent, not something that appeared suddenly Your child's other speech development is on track aside from the lisp
What causes toddler puts tongue between teeth for s sound?
An interdental or frontal lisp, where the tongue slides between the teeth during S and Z sounds (making them sound like TH), is a common developmental pattern in young children. Most children outgrow this by age 4.5. If the lisp persists past this age, speech therapy can help your child learn correct tongue placement. Common explanations include: Your child is under 4.5 years and places their tongue between their teeth for S and Z sounds. Your child's lisp is consistent, not something that appeared suddenly.
What should I mention to my pediatrician about toddler puts tongue between teeth for s sound?
You should mention toddler puts tongue between teeth for s sound at your next visit if: Your child is over 4.5 years and still has a consistent frontal lisp. Your child's lisp is accompanied by other speech sound errors. Your child is starting school and is self-conscious about lisping.
Is toddler puts tongue between teeth for s sound normal at 18-24 months?
S sounds are just beginning to develop. Lisping is not a concern at this age as children are still learning how to position their tongue for different sounds. Many toddlers do not yet produce S sounds at all.
Is toddler puts tongue between teeth for s sound normal at 24-36 months?
An interdental lisp is very common and completely normal during this period. Many children naturally place their tongue between their teeth when attempting S and Z. This usually resolves as oral motor control improves.
Should I go to the ER for toddler puts tongue between teeth for s sound?
Seek emergency care if your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes, or if your child is over 5 years and the lisp is affecting their confidence or willingness to speak. When in doubt, call your pediatrician's after-hours line for guidance.
Does toddler puts tongue between teeth for s sound go away on its own?
In many cases, toddler puts tongue between teeth for s sound resolves on its own, especially when your child is under 4.5 years and places their tongue between their teeth for S and Z sounds. By 5-7 years, a frontal lisp that persists past age 5 is unlikely to resolve on its own and speech therapy is recommended. Treatment is typically effective and straightforward, teaching the child to keep their tongue behind their teeth.
ASHAAAPNIH

References

  1. [1]American Speech-Language-Hearing Association. Speech Sound Disorders: Articulation and Phonology. ASHA
  2. [2]American Academy of Pediatrics. Speech and Language Development. HealthyChildren.org. AAP
  3. [3]National Institute on Deafness and Other Communication Disorders. Speech and Language Developmental Milestones. NIH

Doctor Visit Checklist

Bring this checklist to your next pediatrician visit to discuss Toddler Puts Tongue Between Teeth for S Sound.

Things to mention

  • Describe when you first noticed toddler puts tongue between teeth for s sound and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if your child is over 4.5 years and still has a consistent frontal lisp.
  • Mention if your child's lisp is accompanied by other speech sound errors.
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

Observations to share

  • Your child is over 4.5 years and still has a consistent frontal lisp
  • Your child's lisp is accompanied by other speech sound errors
  • Your child is starting school and is self-conscious about lisping

Urgent signs to report immediately

  • Your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes
  • Your child is over 5 years and the lisp is affecting their confidence or willingness to speak

My notes

From ismybabyalright.com — free, evidence-based baby health guides

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members

Related Resources

Teething GuideMilestone ChecklistsEarly Intervention DirectoryDevelopmental ActivitiesBaby Sign Language GuideBaby Tracker

Bottom line

Most cases of toddler puts tongue between teeth for s sound are normal. Talk to your pediatrician if your child suddenly developed a lisp they did not have before, which could indicate dental or oral changes.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

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Related Speech Concerns

My Toddler Has a Lisp

Lisps are very common in toddlers and preschoolers who are still learning to make certain sounds. Most children don't master the "s" sound until around age 4-5, so a lisp before then is usually developmentally normal. If your child still has a noticeable lisp after age 5, or if it's affecting their confidence, a speech evaluation can help.

Toddler Has a Slushy S Sound (Lateral Lisp)

A lateral lisp produces a "slushy" or wet-sounding S and Z, caused by air escaping over the sides of the tongue rather than through the center. Unlike a frontal lisp (tongue between the teeth), a lateral lisp is not considered a normal developmental pattern and typically requires speech therapy to correct. If you notice this sound quality in your child, a speech-language evaluation is recommended.

Child Cannot Say the S Sound

The S sound is typically mastered between ages 3 and 5. Many young children substitute TH or T for S, which is normal developmental variation. A frontal lisp with S is common and often resolves by age 4.5. If S errors persist past age 5, or if your child has a lateral (slushy) lisp, a speech evaluation is recommended.

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Will Ear Tubes Help My Child's Speech?

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