How to teach the TH sound

Check the age before you start

TH comes late. A five-year-old who says "free" for "three" is usually right on time. Most children get a clear TH between 6 and 8. So the first question is not how to fix TH. It is whether TH is ready to be fixed.

The table below is a rough guide. It is not a test, and every child is different.

Two TH sounds, and which to teach first

English has two TH sounds. They use the same tongue shape. The only difference is the voice.

The quiet TH is just air, like in "thumb" and "three". The buzzy TH turns the voice on, like in "this" and "mother". Put a hand on your throat and you can feel the buzz on the second one.

Teach the quiet TH first. It is easier to hear and easier to feel, because there is nothing to do except blow. Once your child has it, the buzzy one is a short step: same shape, add the voice.

Step 1: Help your child hear the difference

A child who says "fumb" often hears it as right. F and TH sound very alike, even to adults on a phone call. So begin with listening, not speaking.

1. 1Thumbs up, thumbs down. Say words with a real TH or a sneaky F. Your child gives a thumbs up for TH and a thumbs down for F.
2. 2Catch the grown-up. Say "I have free fings" on purpose. Children enjoy catching an adult out.
3. 3Same or different. Say pairs like "three" and "free", or "thin" and "fin", and ask if they match.
4. 4Watch the mouth. Let your child look at your face as you say "thumb" and "fun". TH shows the tongue. F shows the top teeth on the lip.

Step 2: Find the sound

Sit next to your child at a mirror. Show the shape first, then ask them to copy it. Keep it a game.

Help Me Talk uses the same cue on its TH level: "Stick your tongue out a tiny bit between your teeth. Blow air gently." The tongue tip sits between the upper and lower front teeth. The lips stay open and do not touch the tongue.

1. 1Tongue peek. Ask your child to show you a tiny bit of tongue between the teeth. See who can show the smallest bit.
2. 2Blow. Keep the tongue there and blow gently, with no voice. That long, soft hiss is the quiet TH.
3. 3Feather or tissue. Hold a small piece of tissue in front of the mouth. A good TH makes it move a little.
4. 4Watch the lip. If the top teeth land on the bottom lip, that is an F. Ask your child to lift the lip away and let the tongue come forward.
5. 5Add the buzz. When the quiet TH is easy, keep the same shape and hum. That is the buzzy TH.

Step 3: Hold the sound alone

When your child makes a good TH, even once, praise it and ask for it again. Then ask them to hold it for three seconds, like a slow puff of air. A long TH is easier to feel than a short one.

Keep going until your child can make a clear TH about eight times out of ten. Only then move to words. If you skip this step, the F tends to come back the moment a real word is added.

Step 4: Build up one step at a time

Each step below needs its own practice. Do not move up until the step before feels easy. A child can be at a different step for the quiet and the buzzy TH, and that is fine.

TH at the start of a word is usually easiest to start with, because the child can set up the tongue before any other sound. TH at the end, like in "bath", comes next.

Help Me Talk follows the same ladder. The TH level shows how to make the sound, then words, 50 phrases and 50 sentences, so you can work through it in order.

A simple five-minute routine

Count the good tries, not the mistakes. A child needs many good repetitions for TH to become automatic. Aim for 30 to 50 clear tries in a session if your child has the energy, and stop earlier if they do not.

1. 1Warm up (1 minute). Tongue peek and a few long blows at the mirror.
2. 2Listen (1 minute). Play thumbs up, thumbs down with three or four word pairs.
3. 3Practise (2 minutes). Say eight to ten words at your current step. Say each one together, then let your child say it alone.
4. 4Play (1 minute). End with a game, like counting "one, two, three" with a big TH on three. Always end on a win.
5. 5Same time each day. After brushing teeth works well, since your child is already at a mirror.

Problems and fixes

Most children get stuck at the same few places. Here is what to try.

TH and a lisp are not the same

Some children put the tongue between the teeth for S as well, so "sun" sounds like "thun". That is a lisp, and the fix is the opposite: the tongue needs to hide behind the teeth for S. If your child does this, see our guide on how to fix a lisp.

Teaching TH will not cause a lisp. Children learn that TH shows the tongue and S hides it. Practising both side by side can even help, because the difference is easy to see in a mirror.

Let your child hear their own TH

Children often cannot hear their own swaps, because F and TH sound so alike. A recording helps, because they hear the difference when it plays back.

In Help Me Talk, your child says the word and the app listens. It gives a sound accuracy score, with a pass target of 80. If TH slips, it shows what it heard and asks for another try. The TH level is part of the Help Me Talk subscription. The app does not replace a speech-language pathologist. It gives the repeats, which are the part that is hard to fit into a busy day.

When to ask for help

Ask a speech-language pathologist if your child is over 8 and has no clear TH, if other sounds are also wrong, if people often cannot follow their speech, or if your child feels upset about how they talk. A therapist can watch the mouth and give feedback that no guide can.

If your child is under 6 and says F or D for TH, there is usually nothing to fix. Wait, play, and listen.