/θ/ voiceless – as in think
/ð/ voiced – as in this
The English interdental sounds /θ/ and /ð/ — the famous “th” — have no direct equivalent in Portuguese. That’s why they are often tricky for learners.
👅 Correct tongue position:
Your tongue goes between your upper and lower teeth — just enough so you can gently blow air (for /θ/) or use your voice (for /ð/).
⚠️ Common Substitutions (and Why They’re a Problem)
Many learners mistakenly replace:
- /θ/ with /ts/
- /ð/ with /dz/
Others go further and substitute:
- /θ/ with /s
- /ð/ with /z
These substitutions are not acceptable in clear English pronunciation, because they can change the meaning of words — a process called neutralization of contrast.
🔄 See the difference for yourself:
| Correct Word | Learner’s Substitution | Meaning Changes? |
|---|---|---|
| math /mæθ/ | mats /mæts/ | Yes – completely different word! |
| breathe /brið/ | breeds /bridz/ | Yes – noun vs. verb confusion |
| thin /θɪn/ | sin /sɪn/ | Yes – totally different word! |
| thick /θɪk/ | sick /sɪk/ | Yes – again, very different |
| breathe /brið/ | breeze /briːz/ | Yes – verb vs. noun, different root |
🎧 Now it’s your turn!
Take the time to watch and repeat with these two helpful videos that show you exactly how to pronounce the “TH” sounds:
🎯Mini Quiz: Can You Hear the Difference?
👉 Say these word pairs out loud. Can you feel the difference between /θ/ (voiceless) and /ð/ (voiced)?
- think / sink
- thick / sick
- breath / breathe
- then / den
- they / day
✔ Tip: /θ/ feels like a whisper. /ð/ has voice.
✨ Poetic Practice Sentences
Practice these rhythmic and literary phrases to develop fluency and sensitivity to the sounds:
-
“Think of things that thrill your thoughts.”
(Notice all the soft /θ/ sounds.) -
“This and that, these and those – the threads that tie our prose.”
(/ð/ as in this, that, these, those – all voiced.) -
“With every breath, I feel the breeze.”
(contrast between breathe /ð/ and breeze /z/) -
“Thin lines of thought thread through the thick of night.”
(a mix of /θ/ and poetic rhythm)
📝 Writing Task
- Write one sentence using at least two words with /θ/.
- Write one sentence using at least two words with /ð/.