A complete pronunciation guide to the /θ/ and /ð/ sounds in English. Includes tongue placement, practice sentences, and minimal pairs for Spanish speakers.
If you grew up speaking Spanish, the English "TH" sound is one of the trickiest obstacles on the road to fluent pronunciation. It doesn't exist in Spanish phonology, which means your brain has never had to produce it before — and your mouth needs to learn completely new muscle memory.
The good news: this is one of the most teachable sounds in English. Give it focused practice and you'll master it faster than you think.
Spanish has 27 phonemes. English has 44. Several English sounds don't exist in Spanish — and the "TH" family is at the top of that list. When Spanish learners encounter words like think, the, those, or this, the brain searches for the closest native sound and finds:
None of these substitutions is correct, and native speakers often struggle to understand words when these substitutions are made — especially in fast conversation.
English actually has two distinct TH sounds that share the same spelling. This trips up even advanced learners.
Symbol: /θ/
Voiced? No — your vocal cords are NOT vibrating.
Examples: think, three, tooth, bath, month, thousand, author
Symbol: /ð/
Voiced? Yes — your vocal cords ARE vibrating.
Examples: the, this, that, those, them, breathe, father, smooth
The difference between /θ/ and /ð/ is the same difference between /s/ and /z/, or /f/ and /v/ — air escaping through the same mouth position, but with or without vocal cord vibration.
(Listen in Voza for the audio version)
Quick test: Say the letter "S" — now slide your tongue forward until it touches the back of your upper teeth. That forward, airy position is /θ/.
The position is identical to /θ/, but now add voice:
Quick test: Put two fingers gently on your throat (Adam's apple area). For /ð/, you should feel vibration. For /θ/, nothing.
(Listen in Voza for the audio version)
Minimal pairs are pairs of words that differ by only one sound. These are gold for training your ear and mouth simultaneously.
| /θ/ (TH) | /s/ (S) | |-----------|---------| | think | sink | | three | free → Actually /θ/ vs /f/ too | | thank | sank | | path | pass | | math | mass | | month | once (roughly) |
| /θ/ (TH) | /t/ (T) | |-----------|---------| | think | tink (not a word — that's the error!) | | three | tree | | thick | tick | | thread | tread | | bath | bat | | tooth | toot |
| /ð/ (TH) | /d/ (D) | |-----------|---------| | them | Dem (name) | | those | doze | | though | dough | | breathe | breed | | father | fodder| | other | udder |
Say these out loud, slowly at first, then at natural speed. (Listen in Voza for audio pacing)
There's no 100% rule, but patterns exist:
Usually /θ/ (voiceless):
Usually /ð/ (voiced):
Hold a pencil lightly between your front teeth (not biting, just barely touching). Try to speak sentences with TH words. This forces your tongue forward into correct position.
Start saying /s/, then slowly slide your tongue tip forward until it touches the back of your upper teeth. That end position — with air still flowing — is /θ/.
Shadowing means listening to native speech and repeating immediately, matching rhythm and sounds. Voza's AI coach listens in real time and flags TH errors specifically, so you know exactly when you're substituting /t/ or /d/.
Check your current pronunciation score and see how you rank on the TH categories.
Most common substitution: T for /θ/ and D for /ð/.
"I tink" instead of "I think."
Focus on: voiceless TH words — think, thought, three, thank you.
Common substitution: F for /θ/ in certain positions.
"free" instead of "three."
Focus on: voiceless TH, especially at the start of words.
Common substitution: similar to Mexico; occasionally S in some dialects.
Strong interference from the /ʒ/ (like English "measure") — keep that separate.
Why spend time on TH specifically? Because it shows up in the most common words in English:
Mispronouncing these words affects every sentence you speak. Fixing TH pronunciation has a disproportionate positive impact on how fluent you sound to native speakers.
| Sound | IPA | Position | Example words | Common Spanish error | |-------|-----|---------|--------------|---------------------| | Voiceless TH | /θ/ | Tongue tip touches back of upper teeth; no voice | think, three, tooth, bath | /t/ or /s/ or /f/ | | Voiced TH | /ð/ | Same position; vocal cords vibrate | the, this, that, they | /d/ or /z/ |
The /θ/ and /ð/ sounds are difficult because they're new, not because they're complex. With 10 minutes of deliberate practice per day, most Spanish speakers notice a clear improvement within two to three weeks. Start today.
Coaches, linguists, and people from Latin America who learned English by speaking. We write what would have helped us.
