The Top 5 Problematic Sounds in American English: The TH Sound

By Julie Cunningham, MA, CCC-SLP, licensed speech-language pathologist

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What is the TH sound?

Short answer: English has two TH sounds. The voiceless TH /θ/ in think is made with air only, and the voiced TH /ð/ in the adds vocal cord vibration. For both, the tip of your tongue comes out between your top and bottom teeth, your top teeth rest lightly on it, and the air flows out between your tongue and your top teeth.

	Voiceless TH	Voiced TH
IPA symbol	/θ/ (theta)	/ð/ (eth)
Vocal cords	Off: you hear only air	On: you feel a buzz in your throat
Examples	think, three, math	the, mother, breathe
Common mistakes	T, S or F: "tink," "sink," "free"	D or Z: "dis," "zis"

Below I show you how to make both sounds, step by step. Then you'll find TH word lists and the most common TH mistakes.

This is Part Two of the Top 5 Problematic Sounds in American English. As I mentioned in the previous blog, your native language may differ from another person reading this blog, so these sounds may or may not be challenging for you. But based on my experience with accent modification, most people have difficulties with these same 5 sounds, regardless of their native language. So let’s continue with the next sound: The TH sound. Related video: The Top 5 Problematic Sounds in American English: The "r" Sound.

Can you hear the difference between thing and sing? Test your ear with the free 2-minute American English listening quiz.

 

The TH sound is relatively unique to English, and when I introduce this sound to many of my beginner students, they are surprised at the way it is articulated. “You stick your tongue out like that?” And I answer, “Yes...and I don’t know why. That’s just the way it is!”

 

The TH sound is in the words the, three, breath, and mother, and it is represented in the IPA (International Phonetic Alphabet) by these symbols: /θ/ for the voiceless TH sound, and /ð/ for the voiced TH sound (we’ll talk about voicing a little later).

 

The TH sound is unique because of the placement of the tongue when you say this sound. It’s going to feel strange when you do this, but trust me - this is how it’s done! To make the TH sound, place the tip of your tongue between your top and bottom teeth. Once the tip of your tongue is sticking out between your top and bottom teeth, lightly place your top teeth down onto your tongue. It should look like this:

 

 

Now that you know the tongue placement, let’s talk more about voicing. Voicing refers to the vibration of your vocal cords - either your vocal cords are vibrating, or they are not. And the difference between the two TH sounds /θ/ (three) and /ð/ (the) is voicing.

 

To understand the concept of vocal cord vibration, try this quick exercise. Place your hand on your throat and breathe. What do you feel? You should feel...nothing. While you’re breathing, your vocal cords are wide open, and air is just passing through unobstructed. Now keeping your hand on your throat, say the word “hot” and hold out the first sound “hhhhh”. You should feel no vibration of your vocal cords - just the air is moving. This is the same airflow that you use for the voiceless TH sound /θ/.

 

Now say the word “me” as you keep your hand on your throat. What do you feel this time? You should feel vibration or movement of your vocal cords. When a sound is made with the vocal cords vibrating, we call it a voiced sound. The word this is made with the voiced TH sound /ð/. You should feel vibration in your throat when you say that first TH sound.

 

Now you understand the concepts of tongue placement and voicing, let’s start practicing. Place your tongue between your teeth like is shown in the picture above. To make a voiceless TH sound, blow air out of your mouth and direct the airflow through the space between your top teeth and tongue. If the air flows out the sides of your tongue, it will sound like a lisp (think Sylvester the Cat).

 

To make the voiced TH sound /ð/, all you need to do extra is turn on your vocal cords, or make them vibrate. When you do this, you should feel a vibration not only in your throat but also between your top teeth and tongue where the airflow is moving. If there isn’t vibration happening there, then it will sound like an L sound.

 

The TH is one of five sounds that trip up nearly every speaker I work with. I cover all five, with drills for each, in the Top Pronunciation Challenges course inside English Pro.

 

Listen to a few words with the voiceless TH /θ/ sound: think, three, breath, mouth.

 

Listen to a few words with the voiced TH /ð/ sound: the, this, either, mother.

 

TH words: voiced and voiceless

Here are common TH words, sorted by where the TH comes in the word. Say each one slowly, with the tip of your tongue between your teeth. For the voiced words, put your hand on your throat and feel the buzz.

Position	Voiceless TH /θ/	Voiced TH /ð/
Beginning	think, thank, three, thing, thought, through, thumb, Thursday, thousand	the, this, that, these, those, they, them, there, then, though
Middle	nothing, birthday, author, method, healthy, bathroom, athlete, everything	mother, father, brother, other, weather, together, either, rather
End	math, bath, breath, teeth, mouth, north, south, both, health, truth, month	breathe, bathe, smooth, soothe, clothe, teethe

Spelling tip: words that end in -the usually have a voiced TH, and words that end in -th usually have a voiceless TH. That's why breath and breathe sound different, and so do bath and bathe.

Common TH mistakes

If your first language doesn't have a TH sound, your mouth will reach for the closest sound it knows. Here's what that sounds like to an American listener:

• T instead of voiceless TH: thin sounds like tin, and three sounds like tree.
• S instead of voiceless TH: think sounds like sink, and path sounds like pass.
• F instead of voiceless TH: three sounds like free, and thought sounds like fought.
• D instead of voiced TH: they sounds like day, and though sounds like dough.
• Z instead of voiced TH: then sounds like Zen, and breathe sounds like breeze.

Each mistake has a simple cause. If the air stops, the TH turns into a T or D. If the tongue tip pulls back and points down behind your teeth, it turns into an S or Z. If your top teeth touch your lower lip instead of your tongue, it turns into an F.

More TH practice

Watch my 4 tips for the TH sound, with practice sentences, and see both TH sounds close up and in slow motion, including the shorter TH that native speakers use in the, this and that.

TH sound: common questions

What are the two TH sounds in English?

Voiceless TH /θ/, as in think, three and math, is made with air only. Voiced TH /ð/, as in the, mother and breathe, adds vocal cord vibration. Your tongue and teeth are in the same position for both.

What is the symbol for the TH sound?

The International Phonetic Alphabet uses /θ/ (the Greek letter theta) for the voiceless TH and /ð/ (a letter called eth) for the voiced TH.

How do I know if a TH is voiced or voiceless?

The spelling doesn't tell you, but a few patterns help. Small everyday words like the, this, that, they, there and then have a voiced TH. Most other words that start with TH, like think, three and thank, have a voiceless TH. A final -the, as in breathe and bathe, is voiced, and a final -th, as in breath and bath, is usually voiceless. When in doubt, listen to a dictionary's audio.

Do I have to stick my tongue out to say TH?

Only the tip, and not far. For the voiceless TH, the tip always comes out between your teeth. For a voiced TH at the start of an unstressed word, like the, this and that in a sentence, native speakers often just touch the tongue tip to the back of the front teeth. It still sounds like a TH.

Why do I say T, S, D or Z instead of TH?

Many languages don't have a TH sound, so your mouth uses the closest sound it knows. Keep the tip of your tongue between your teeth and keep the air moving, and you'll hear the TH.

Is "with" said with a voiced or voiceless TH?

Both are common. Many Americans say /wɪθ/ with a voiceless TH, and many say /wɪð/ with a voiced TH. Either one sounds natural.

I also work with students one-to-one on Zoom. See how private training works.

And stay tuned for upcoming blogs about the next 3 problematic sounds in American English.

 

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This is one of the top pronunciation challenges for native speakers of Farsi/Persian, Filipino/Tagalog, French, Italian, Portuguese and Turkish. See my guides for Farsi/Persian, Filipino/Tagalog, French, Italian, Portuguese and Turkish speakers.

The TH sound trips up almost every learner at first, but it gets easier with repetition - come practice your American accent free on my course platform, with exercises built around sounds like this one.