Speech Sounds by Age: When Kids Learn R, S, L and TH

Your four-year-old says "wabbit" and "fank you". Your mother says you were saying your R's by three. Your neighbour says it is adorable and you should leave it alone. Your pediatrician did not seem bothered.

So who is right? Mostly the pediatrician. But there is a point where "cute" turns into "worth a look", and it helps to know where that point is for each sound.

The chart

In 2020, two researchers, Kathryn Crowe and Sharynne McLeod, pulled together 15 studies covering 18,907 children in the United States and worked out when children learn each English consonant. It is the most complete picture we have, and speech therapists use it.

This table uses their strictest measure: the age by which 9 out of 10 children say the sound correctly. If your child is younger than the age shown, trouble with that sound is expected.

By about age	Sounds most children can say
3	p, b, m, n, d, h, w
3 and a half	t, k, g, f, ng (as in "sing")
4 and a half	y, v, j (as in "jump"), l, s, ch
5	sh, z, zh (as in "treasure")
5 and a half	r
5 and a half to 6	th (voiced, as in "this")
6 and a half	th (voiceless, as in "think")

Two things jump out. The R sound is one of the very last, and the TH in "think" is the last of all. A five-year-old who says "wed" for red is completely typical. A three-year-old who cannot say K or G yet is also within range.

Source: Crowe and McLeod, *Children's English Consonant Acquisition in the United States: A Review*, American Journal of Speech-Language Pathology (2020).

Why kids learn sounds in this order

The early sounds are easy to see and easy to make. You can watch someone's lips close for P, B and M. A baby can copy that.

The late sounds are hidden inside the mouth and need fine control. R needs the tongue bunched or curled in a precise shape without touching much of anything. S needs a narrow groove down the middle of the tongue and air pushed through it. Nobody can see those movements, so children have to work them out by ear and by feel. That takes years.

Being understood matters more than any single sound

A child can have several sounds still to learn and be easy to understand. A child can also have most sounds in place and still be hard to follow, because of the way they simplify whole words.

A rough guide that speech therapists use:

At age 3, people who know your child well should understand most of what they say.

At age 4 to 5, strangers should understand them most of the time.

If a new teacher or a relative who rarely visits cannot follow your four-year-old, that is a better reason to get a check than any one missing sound.

Mistakes that are normal (and ones that are not)

Young children simplify words in predictable ways. Speech therapists call these patterns phonological processes. Most fade on their own by a certain age.

Usually fine, and fades with age:

Leaving off the last sound ("ca" for cat). Most children stop by about 3.

Saying T for K ("tat" for cat). Most children stop by about 3 and a half.

Dropping a sound from a pair ("poon" for spoon). Most children stop by about 4 to 5.

W for R or L ("wabbit", "yewwow"). Can last until 5 or 6.

F for TH ("fumb" for thumb). Can last until 6 or 7.

Worth getting checked at any age:

Leaving off the first sound of words ("at" for cat). This is not a common pattern.

Replacing most sounds with one sound, like H or a sound made in the throat.

The same word coming out differently each time. This can be a sign of a motor planning problem called apraxia. More on that in our [guide to childhood apraxia of speech](/blog/childhood-apraxia-of-speech).

A lisp where the tongue slides to the side, so S sounds wet or slushy. A frontal lisp (tongue between the teeth) is common in young children. A side lisp usually does not go away on its own.

Air coming out of the nose on sounds like P, B, S.

When to get it checked

Talk to a speech therapist if:

your child is past the age in the chart for a sound and still cannot say it at all

strangers struggle to understand your child after age 4

your child is getting frustrated, or other children are commenting

you hear any of the "worth getting checked" patterns above

In the US, from age three your school district will assess your child's speech for free, even if they are not in school yet. Send the request by email so it has a date on it.

Practising at home without turning it into a drill

If your child has a sound they are working on, short and frequent beats long and rare. Ten good tries a few times a day does more than one miserable twenty-minute session on Sunday.

A few rules that make it easier:

Say the sound, not the letter name. "Sss" like a snake, not "ess". Letter names do not help a child say a sound.

Practise the sound in all three places in a word. At the start (sun), in the middle (messy) and at the end (bus). Children often get one position before the others, and a speech therapist will track them separately.

Do not correct every mistake in real conversation. Instead, say the word back correctly. Your child says "I saw a wabbit". You say "a rabbit! Where was the rabbit?" No pressure, and they hear it right.

Stop while it is still fun. Four good tries and a laugh is better than ten tries and tears.

Disclosure: we make Verbalyft, which has games built around exactly this kind of practice. The games work on sounds rather than letter names, track the sound at the start, middle and end of words separately, and leave it to you as the parent to decide whether an attempt counts. You can do all of the above without any app. A pile of picture cards and five minutes after dinner works too.

FAQ

My 3-year-old can't say S. Is that a problem?

No. Most children are closer to four and a half before S is reliable.

My 6-year-old still says "wed" for "red". Should I worry?

It is at the late edge of normal. Nine in ten children have R by around five and a half. A quick check with a speech therapist, often free through school, is reasonable at six.

Will a lisp go away on its own?

A lisp with the tongue between the teeth often does by about five. A side lisp, where the S sounds slushy, usually needs help.

Does tongue-tie cause speech problems?

Less often than people think. Most sounds do not need much tongue lift. If you are concerned, ask a speech therapist to look at speech first, before any procedure is considered.