English TH for Mandarin speakers: think/sink and they/day
If Mandarin is your first language, the TH in think may sometimes move toward /s/, making it sound closer to sink. The TH in they may move toward /d/, making it sound closer to day. Other results are possible too: voiceless TH can come out closer to /f/, and voiced TH closer to a Z-like sound. The pattern depends on the person, word, and speaking context, so this is a possible pattern, not a diagnosis. The feedback on your recordings in Ekavo can point to what happened in a given take.
These changes usually do not prevent understanding because listeners use the rest of the sentence. TH does occur in frequent words such as the, this, that, they, think, and thank, so practicing it can give you more control over a noticeable part of American English. Whether that goal matters to you is your choice.
What’s actually happening
American English has two TH sound categories:
- /θ/ is voiceless, with the voice off, as in think, three, birthday, and mouth.
- /ð/ is voiced, with the voice on, as in this, they, mother, and breathe.
Mandarin does not use /θ/ and /ð/ as consonant categories, so your speech system may select another familiar movement. The result can vary. A teachers’ reference on Chinese speakers, covering speakers of all Chinese dialects rather than Mandarin alone, lists /d/ or /z/ for voiced TH, so this may sound like “dis” or “zis”, and /t/, /f/, or /s/ for voiceless TH.
Tongue position is only part of the difference between TH and S or Z. For /s/ and /z/, the tongue sits behind the teeth and forms a narrow groove that directs a focused jet of air, producing a sharper hiss. TH uses contact at the teeth and less focused friction. /d/ is a stop: the tongue seals, the air stops, then the closure releases. Between the two TH sounds, the main difference is voicing.
These word pairs show what each substitution changes:
| Contrast | Word pairs |
|---|---|
| /θ/ and /s/ | think / sink, thick / sick, path / pass |
| /ð/ and /d/ | they / day, though / dough, then / den |
| /θ/ and /f/ | thin / fin, three / free |
| /ð/ and /z/ | breathe / breeze, clothing / closing |
Control in a slow drill may appear before the same movement is available in fast speech. Frequent words such as the and that are often said quickly and with reduced stress, so TH in them can vary more than in content words.
How to move toward TH
For both sounds, place the tongue tip lightly against the back or lower edge of the upper front teeth. It can also sit just between the teeth. Keep a narrow opening so air continues to flow. Do not bite or push the tongue forward.
A slightly visible tongue tip can be a useful training cue, but it is not a correctness test. A dental TH made just behind the teeth may not be visible in a mirror.
If the sound comes out as a sharp /s/ hiss, move the tongue tip toward the teeth and let the air spread more broadly. If it comes out as /f/, keep the lower lip away from the upper teeth and let the tongue make the contact instead. If they comes out as day, lighten the contact so the tongue does not seal. For /ð/, keep the same tongue position as /θ/ and switch your voice on; /θ/ has the voice off.
Practice it in Ekavo
Every step below uses the app: its American English reference audio, your recordings, and the feedback on them. Recording and reference audio are part of Ekavo Pro, which eligible new subscribers can try free for seven days. Speech match estimates how closely this take aligns with Ekavo’s American English practice target. Treat it as feedback on one take, not a listener’s judgment. The two TH sounds have separate pages; the steps start with /θ/.
- Open the sound. In the Sounds tab, tap /θ/. Play the reference audio at the top of the page, then open Shape /θ/ to watch the mouth and tongue position.
- Record a sentence. Under Practice this sound, open Sentences and record one. After the score appears, tap the TH words. When a TH scores low, the word’s detail can say which sound it was heard as, for example “We heard /s/ where /θ/ belongs.” Use that suggestion as a starting point for this take, not as a verdict on your pronunciation.
- Retry the same sentence. Choose one TH word to focus on, play Coach, and compare it with Your take. Then record the same sentence again and see how that word scored.
- Hear the difference. If Hear the difference appears on the /θ/ page, play both words in each pair, then tap a pair to record both words. Each word gets its own Speech match score. The app chooses this contrast from your first-language information and the available practice words, so it may differ from the comparisons in this article or from your sentence feedback. The target is the same TH either way: a light touch at the teeth and steady air.
- Work word by word. Open Words and record a few. Before each take, play Coach, and use the slower speed if it helps. After scoring, play Your take and compare it with Coach. Follow the TRY NEXT line, then record again. Then return to your sentence and record it once more.
- Move into passages. Try Passages. After each reading, tap the TH words to see how each one scored, choose one to focus on, and read the passage again.
- Repeat for /ð/. Go back to the Sounds tab, tap /ð/, and repeat steps 2 to 6 on /ð/. The tongue position is the same as for /θ/, with the voice on.
- Use it in a conversation. If a TH page shows Roleplays featuring /θ/ or Roleplays featuring /ð/, open one. You read your lines in a short scripted exchange, and each line shows how the target sound came through. Worth revisiting in the summary points to a line to practice again.
A contrast that is clear in a single word may become less clear in a sentence or a conversation, and that gap is normal. TH before a vowel in think and this, at the end of path and breathe, and in clusters in three and throw can each come out differently. This is not a universal difficulty ranking. Let your recordings set the order of practice.