What Is a Lisp? Why Your Child Says "Thun" for Sun, and How to Help

A lisp is when a child cannot say s and z clearly, usually because the tongue is in the wrong place: “thun” for sun, or “thoo” for zoo. Most children say s clearly by about 4–5, so a lisp in a 3- or 4-year-old is often part of learning to talk.

What to do depends on where the air goes. A frontal lisp, with the tongue peeking between the teeth so s sounds like th, is common in children until about 5 and often fades. A lateral lisp, a wet, slushy s with the air escaping over the sides of the tongue, is not part of typical development and is worth a speech-language pathologist’s opinion early. At home, the most useful cue is the snake sound: smile, teeth together, tongue tucked behind them, and a long, gentle hiss. This page covers the four types of lisp, when each usually goes away, what causes one, and how to help.

What is a lisp?

A lisp is a speech sound difference in which s and z, and sometimes sh, ch and j, come out unclear because the tongue is in a different place. A child with a lisp might say “thun” for sun, “yeth” for yes, or “thock” for sock. The word is still easy to recognize; what changes is how the s itself sounds.

A lisp is an articulation difference: a problem making one sound, not a pattern of swapping groups of sounds. The Practice Portal of the American Speech-Language-Hearing Association (ASHA) describes articulation errors as problems with the motor production of a sound and gives “a lateral /s/” as an example. The phonological processes page explains the difference between the two.

A child who says t for s (“toap” for soap) does not have a lisp. That is stopping, one of the patterns young children use while they learn to talk.

What are the different types of lisps?

There are four types of lisp, named for where the tongue goes: frontal, lateral, dentalized and palatal. Two of them are often part of learning to talk, and two are not.

Type	What the tongue does	What it sounds like	Part of learning to talk?
Frontal (interdental)	Pokes out between the front teeth	Like th: “thun” for sun	Common until about 5
Dentalized	Pushes against the back of the front teeth	A muffled s	Common until about 4½
Lateral	Lets air escape over the sides	A wet, slushy s, close to sh	No
Palatal	Touches the roof of the mouth too far back	A mushy, hissy s	No

The ages come from two sources. Whittington Health NHS Trust says a frontal lisp “is common in children until about the age of 5 years and is part of typical speech development” (Whittington Health NHS). Speech-language pathologist Caroline Bowen writes that children “may produce dentalised variants of /s/ and /z/ until around 4½ years - and then grow out of it”, and that palatal lisps “are not found in typical speech development”.

A lateral lisp is the one to act on early. In a lateral lisp the air escapes over the sides of the tongue instead of down the middle, so s sounds wet or slushy, closer to sh: MyHealth Alberta gives “shoap” for soap. Whittington Health NHS Trust says a lateral lisp “is not a part of typical development, and the child may benefit from some support”. It is worth a speech-language pathologist’s opinion at any age.

To tell which one you are hearing, watch your child say “sun” in a mirror. If the tongue tip shows between the teeth, it is a frontal lisp. If the tongue stays in but the s sounds wet, or you can feel air on a hand held beside the cheek, it may be lateral. If you cannot tell, ask.

Is a lisp normal? When does a lisp go away?

A lisp is normal in young children while s is still arriving. A 2020 review of English consonant acquisition by Crowe and McLeod, which pooled 15 US studies covering 18,907 children, found that 90% of children said s and z correctly between 4 years and 4 years 11 months. MyHealth Alberta’s speech sound activities, presented by a pediatric speech-language pathologist, tell parents “most children can make this sound correctly by 5 years of age” (MyHealth Alberta).

A frontal lisp usually fades by about 5, and a dentalized one by about 4½. Both are common in children who are still learning s, and many children grow out of them without help.

Lateral and palatal lisps are different. Neither is part of typical development, and Bowen writes that a child with either “should be assessed, by a qualified speech-language pathologist/speech and language therapist, without delay”. She adds that, in most clinicians’ experience, children are more likely to grow out of a frontal or dentalized lisp than a lateral or palatal one, while noting that studies to confirm it are unavailable.

So it is worth asking a speech-language pathologist about:

• a lateral or palatal lisp, at any age;
• a frontal or dentalized lisp still there after about 5;
• any lisp that is upsetting your child or getting in the way at school;
• any lisp you are worried about.

What causes a lisp?

Most lisps have no known cause: the child has learned to make s a different way, and it has become a habit. Speech and Language UK, a children’s communication charity, puts it directly: “There is no known cause of a lisp” and “For most children, they have simply learned to say a ‘s’ sound differently, and this has become a habit” (Speech and Language UK).

Dummies, bottles and thumb-sucking are often blamed, but the evidence is weak. Speech and Language UK lists long-term use of dummies or bottles and the position of the jaw, teeth and tongue as things “traditionally been linked to lisps, but there is no strong evidence”. A review of the research on dummies and speech by Strutt, Khattab and Willoughby (2021) concluded that “the evidence base for any effects of dummy use on speech is very small”. Dentists advise stopping sucking habits by about 3 for the sake of the teeth, as ASHA’s page on orofacial myofunctional disorders notes.

Losing front baby teeth early may make s harder for a while, but a review by Nadelman and colleagues (2020) rated that evidence as low certainty. A speech-language pathologist may also check hearing, because hearing loss can affect how speech sounds develop, as ASHA’s page for families (ASHA) notes. Rarely, a physical difference in the mouth is involved, which is one more thing an evaluation looks for.

Tongue thrust goes with a frontal lisp, but it is not known to cause it. Tongue thrust is “protrusion of the tongue between the teeth”, which “may impact swallowing and articulation”, according to the Practice Portal page on orofacial myofunctional disorders from ASHA. ASHA lists “distorted productions of /s, z/, often with an interdental lisp” among its signs, but says the evidence “does not indicate causation”. A speech-language pathologist assesses tongue thrust as part of a team that can include a dentist or orthodontist.

Can a lisp be fixed? How a speech-language pathologist treats it

Yes: a lisp in a young child usually responds well to speech therapy. Bowen writes that “speech pathology intervention for lisps in young children is usually short-term and successful”. Speech and Language UK adds that therapy “works best when a child wants to work on their lisp”.

Therapy builds the new s in small steps. Bowen describes the usual sequence:

1. The s sound on its own.
2. The s in syllables (see, saw, sigh).
3. The s in words, one position at a time, often starting with s at the beginning of the word.
4. The s in short phrases and sentences.
5. The s in everyday talk.

A speech-language pathologist decides where your child starts and when to move on, and gives you words to practice at home between sessions. That practice is why the s words for speech practice are sorted by where the s falls in the word.

How to help a child with a lisp at home

Help a child with a lisp by modeling a clear s, showing where the tongue goes, and practicing a few s words for 5–10 minutes most days. Whittington Health NHS Trust’s first tip is to model the word rather than correct it: if your child says “I want to wear the blue thock”, answer “Here’s your blue sssock”. “Children learn a lot about speech sounds through listening.”

1. 1

   Model a clear s

   When your child says a word with a lisp, say it back clearly without asking them to repeat it: if they ask for the blue thock, hand it over with Here is your blue sssock.

2. 2

   Show the snake sound

   Smile, put your teeth together, keep your tongue tucked behind them and blow a long, gentle sssss. Do it in a mirror together so your child can see that the tongue stays in.

3. 3

   Practice 4 or 5 s words

   Pick 4 or 5 everyday s words, such as sock, soap, sun and bus, and use them in play for 5–10 minutes most days. Stop while your child still wants to play.

4. 4

   Praise the try

   Do not correct every word. Praise the try, and if your child sees a speech-language pathologist, use their words and targets instead of this list.

The snake-sound cue is MyHealth Alberta’s: “When you make a ‘s’ you smile, put your teeth together and gently blow some air.” Whittington suggests using a mirror “to demonstrate how the tongue stays behind the teeth when making a /s/ sound”, with “4 or 5 simple /s/ words that you and your child say lots each day”. MyHealth Alberta adds the rule that keeps practice positive: “Don’t correct them when they make a mistake.”

If your child sees a speech-language pathologist, follow their targets over this page’s. Practice at home works best on the words and the position they are working on.

S and z practice words: beginning, middle and end

S and z practice words are sorted by where the sound falls: at the beginning (sun, zoo), in the middle (pencil, lizard) or at the end (bus, nose). A speech-language pathologist often works on one position at a time, frequently starting with s at the beginning of words, as in Bowen’s worked example, though no source sets one order for every child.

A first set for a child with a lisp:

Position	S words	Z words
Beginning	sun, sock, soap, seal	zoo, zebra, zipper
Middle	pencil, dinosaur, basket	lizard, puzzle
End	bus, house, mouse, juice	nose, cheese, bees

Choose words with one s and no s blend, and avoid sauce and sister on a first set. The full lists, 36 s words and 24 z words with picture cards for each position, are on the page of s and z words for speech practice. S blends such as spoon and star are a separate skill, practiced for reading on the s blends page.

Free PDF · no sign-up

Free printable s and z cards, cue cards and practice log

S and z picture cards sorted by where the sound falls in the word, from the s and z words page, plus speech sound cue cards for the grown-up and a 5-minute practice log from the minimal pairs page. No account, no email.

1. 1Articulation Picture Cards (PDF)60 cards for S and Z · 7 pagesDownload
2. 2Speech Sound Cue Cards (PDF)7 sounds · 4 pagesDownload
3. 35-Minute Speech Practice Log (PDF)5 days · 1 pageDownload

Lisp practice with minimal pairs

Minimal pairs help a child with a lisp hear that s and th make different words. A minimal pair is two words that differ by one sound, such as sink and think. When a child hears that saying “think” for sink changes the word, they have a reason to change the sound.

Pairs that suit a lisp:

• S and th: sink and think, mouse and mouth, moss and moth. These are on the th minimal pairs page, with picture cards.
• S and sh, and s and z: sip and ship, sip and zip. These are on the s and sh minimal pairs page.

The method, the games, and a 2-minute picture check for the common speech patterns are on the minimal pairs page.

Does a lisp affect a child’s confidence?

Most young children do not notice their own lisp, but some older children are teased about it. A child of 3 or 4 usually has no idea their s sounds different. By school age, other children may notice and comment.

If another child comments or teases:

• Name it calmly. Tell your child that lots of people say some sounds differently, that it is not their fault, and that it can be practiced.
• Practice a reply. A short, calm line such as “I am still learning my s sound” takes the sting out of a comment.
• Tell the teacher. A teacher can stop teasing in class and keep an eye on it.

Keep practice private. Never practice in front of other children, and do not turn mealtimes into correction time. If a lisp is upsetting your child, that alone is reason enough to see a speech-language pathologist, whatever their age.

When should I see a speech-language pathologist about a lisp?

See a speech-language pathologist for a lateral or palatal lisp at any age, a frontal or dentalized lisp still there after about 5, a lisp that is affecting your child at school or with friends, or any time you are worried. A parent’s worry is reason enough. Whittington Health NHS Trust says a child with a lateral lisp “may benefit from some support from a Speech and Language Therapist”, and Bowen writes that lateral and palatal lisps should be assessed “without delay”.

An evaluation usually means listening to your child say s and z in words and sentences, looking at how the tongue moves, and sometimes checking hearing. It tells you which type of lisp your child has and whether therapy would help. ASHA ProFind lists certified speech-language pathologists. Once therapy starts, you can keep the s practice going between sessions with the routine and games in speech therapy at home.