English has two th sounds. The is in think, three and bath, and the is in this, that and mother. For both, touch the back of your top front teeth with the tip of your tongue and let the air flow. When you practise slowly, you can let the tip show a little between your teeth. For , add your voice.
Two sounds, one spelling
The spelling th stands for two different sounds in English. They are made in the same place and in the same way. The only difference is the voice.
The th, , is breath only. You hear it in think, three, thank, month and bath. The th, , uses your voice. You hear it in this, that, the, mother and breathe. Put your fingers on your throat. For you feel a buzz, and for you do not.
- think · this
- three · they
- bath · bathe
- thing · then
How to make the sounds
Touch the back of your top front teeth with the tip of your tongue. When you practise slowly, you can let the tip show a little between your teeth, but do not bite it. The tongue is flat and relaxed, and a thin stream of air flows over it.
For push air out quietly, as if you are blowing on hot soup. For , make the same shape and turn on your voice. The sound should buzz a little. If your tongue goes back and touches the ridge, you will say or . If your teeth press on your lower lip, you will say or .
- Tongue tip: light contact with the top teeth.
- Air: a continuous flow, not a stop.
- Voice: off for , on for .
- Lips: relaxed, not touching each other.
Which th is it? Simple rules
Most of the time you can choose with these rules. They are not perfect, but they cover most common words.
- Grammar words are : the, this, that, these, those, they, them, then, there, than, though.
- Many words with th between are voiced: mother, father, brother, weather, together, other, rather. There are exceptions, such as author and method.
- Most other words are : think, thing, thank, three, thirty, throw, theory, health, month, truth.
- Nouns ending in th are usually voiceless: bath, mouth, tooth, month. The matching verbs, such as bathe, are voiced.
- A few words keep the t sound: Thomas, Thames, Thailand.
Noun and verb pairs
Some pairs of words change from to when the word is a verb. Bath is /bɑːθ/, but bathe is /beɪð/. Breath is /breθ/, but breathe is /briːð/. Cloth is /klɒθ/, but clothe is /kləʊð/. Mouth as a noun is /maʊθ/, but to mouth is /maʊð/. These pairs matter because a different sound means a different word.
Common mistakes
The most common mistakes are replacements. Many learners say or (sink for think, zis for this), or (tree for three, dis for this), or and (fink for think, vat for that). These are understandable, but the listener may hear a different word.
Another mistake is pushing the tongue too far out, so the sound is too long. A light touch is enough. A third mistake is forgetting the voice on in the very common little words. The, this, that and they are used constantly, so even a small improvement in these words is clearly heard.
Practice routine
Begin with a mirror. Say 'thhh' with the tip of your tongue touching the back of your top front teeth (you may see a little of the tip between your teeth). Add voice for 'thhh' as in this. Then say pairs that contrast the sounds you replace, such as think and sink, three and tree, this and zis. Move to short phrases: 'this thing', 'the three of them', 'another month', 'together with my brother'.
Finish with an IELTS-style sentence: 'I think that the weather in my home town is better than in the north.' Say it slowly and listen to each th. Do this for a few minutes every day, and remember that you can only hear the difference if you keep the tongue forward.
How to make the sound
- Touch the back of your top front teeth with the tip of your tongue, without biting it.
- For , blow air out gently with no voice: 'think'.
- For , make the same shape and turn on your voice so you feel a buzz: 'this'.
- Pull the tongue back quickly into the next sound, without a stop.
Who finds this hard?
- Japanese speakers: Japanese does not have either th sound, so learners often use or . Practise touching the back of the top front teeth with the tongue tip, and listen for think against sink.
- Italian speakers: Italian has no th sounds, so learners often say and , giving 'tink' and 'dis'. A light tongue touch with the air flowing helps.
- Spanish speakers: Speakers from Spain already use in words like zapato and cielo, so they can use that sound. Many Latin American speakers use for it, and the at the start of words like this needs practice, because Spanish has it only between , as in the d of nada.
IELTS tip
The th sounds appear in some of the most common words in English, including the, this, that, they, think and thing. In the Speaking test, a clear th in these small words makes your whole speech clearer. Practise a few phrases that you will use in Part 1, such as 'I think that', 'the three of us' and 'my brother and I'.
Frequently asked questions
How do you pronounce th in English?
Touch the back of your top front teeth lightly with the tip of your tongue and let air flow. Use no voice for think, and add your voice for this.
When is th voiced and when is it voiceless?
It is in grammar words like the, this and they, and in words like mother and brother. It is in most other words, such as think, three and month.
Can I say s or t instead of th in IELTS?
Many learners do, and they can still be understood in context. But a clear th avoids confusion between words like think and sink, and it makes your speech sound more natural.
Why is th so hard?
Many languages have no th sounds. The tongue position is unfamiliar, and the sounds look similar in spelling but differ in voice.
Sources
- Roach, P. (2009). English Phonetics and Phonology: A Practical Course (4th ed.). Cambridge University Press.
- Cruttenden, A. (2014). Gimson's Pronunciation of English (8th ed.). Routledge.