How to pronounce th: /θ/ and /ð/
Short answer: The letters th have two sounds. /θ/ is voiceless, as in think, three and bath. /ð/ is voiced, as in this, they and mother. For both, put the tip of your tongue lightly between or against your front teeth and let air pass. For /θ/ you feel only air; for /ð/ you feel a buzz in your throat.
▶ Open the sound card Practice →
At a glance
| Sound | Voice | Examples | Not this |
|---|---|---|---|
| /θ/ | voiceless (air only) | think, three, thank, bath | sink, tree, tank, bass |
| /ð/ | voiced (buzz) | this, they, mother, breathe | dis, day, mudder, breeze |
How to make the sound
- Smile a little and let the tip of your tongue touch your front teeth.
- Blow air gently. For /θ/ the air makes a soft hiss and you feel no buzz.
- For /ð/ add your voice. Touch your throat: you should feel the buzz.
- Pull the tongue back and say the next vowel. Do not stop the air completely.
Pairs to practice
| With th | Without th |
|---|---|
| think /θɪŋk/ | sink /sɪŋk/ |
| three /θri/ | tree /tri/ |
| thank /θæŋk/ | sank /sæŋk/ |
| they /ðeɪ/ | day /deɪ/ |
| then /ðɛn/ | den /dɛn/ |
| bath /bæθ/ | bass /bæs/ |
Examples in sentences
- I think this is the third one.
think /θ/, this /ð/, third /θ/. - Thank you for the birthday gift.
thank /θ/, birthday /θ/, the /ð/. - My mother and father are here.
mother and father: /ð/ in the middle. - They bought three thick books.
they /ð/; three, thick /θ/. - Breathe slowly, then relax.
breathe /ð/; then /ð/. - The weather is good today.
weather: /ð/ in the middle. - He has a bath every Thursday.
bath /θ/; Thursday /θ/. - That is the fourth question.
that, the /ð/; fourth /θ/.
Common problems
- Replacing with /s/ or /t/: Saying sink for think or tree for three changes the word.
- Replacing with /d/ or /z/: Saying day for they or dis for this is common. Keep the tongue at the teeth and let the air continue.
- Forgetting to voice /ð/: If you feel no buzz in this and they, add your voice.
For Vietnamese speakers
- Vietnamese does not have /θ/ and /ð/, so learners often use /t/ or /s/ for /θ/, and /d/ or /z/ for /ð/. Practice with the tongue visible in a mirror.
- Start with a long /θθθ/ and a long /ððð/. Then add the vowel: thhh-ink, thhh-ree.
/θ/ and /ð/ at a glance
The mouth position is the same. Only the voice changes.
| /θ/ | /ð/ | |
|---|---|---|
| tongue | tip at the teeth | tip at the teeth |
| voice | none (air only) | buzz |
| words | think, three, bath | this, they, mother |
Check yourself
- Which word starts with /θ/: “this” or “think”?
Show the answer
think think is voiceless /θ/; this is voiced /ð/.
- What happens if you say “sink” for “think”?
Show the answer
The word changes. sink starts with /s/, not /θ/.
- How can you feel the difference between /θ/ and /ð/?
Show the answer
Touch your throat. /ð/ has a buzz; /θ/ does not.
Questions
Are all th words the same sound?
No. There are two sounds. Function words such as the, this, that, they and then have /ð/. Content words such as think, three and thank have /θ/.
Why do some people say /f/ for th?
In some accents, three becomes free. In standard English /θ/ is kept, so pronounce it with the tongue at the teeth.
Is th silent in Thomas?
In the name Thomas, th is /t/: /ˈtɑməs/. Names and a few other words are exceptions.
More lessons in this part
- sh or s? ship, sip
- Short i or long ee? ship, sheep
- ch, sh or j? chip, ship, jam
- l, r or n? light, right, night
- a, e or u? bag, beg, bug
Part of the 👄 Pronunciation tool: Sound Contrast & Articulation. See also the English pronunciation guide. Đọc bằng tiếng Việt.
Written for English learners by the English for Fun team. How we write our lessons · Last updated 2026-11-05.
Reviewed by Chinh Q. Hoang, PhD, founder, English for Fun · 2026-10-30
← Short i or long ee? ship, sheep ch, sh or j? chip, ship, jam →