How to Pronounce the TH Sound in English (Both Types)

How to pronounce TH sound combinations in English without sounding non-native? Place your tongue tip lightly between your front teeth and push air through. English has two TH sounds, most languages have neither, and the substitution you make reveals which language you grew up speaking. This guide on how to pronounce TH sound pairs accurately covers the mechanics, L1-specific fixes, the top 20 high-frequency TH words to drill, minimal pairs, four self-check tests, and silent TH in fast speech.

Quick Summary: Place your tongue tip lightly between your top and bottom front teeth and push air through. If your vocal cords buzz, you get voiced /ð/ as in "this." If they don't, you get voiceless /θ/ as in "think." Function words (the, this, that) use voiced TH; content words (think, three, bath) use voiceless TH.

The Two TH Sounds: Voiceless /θ/ and Voiced /ð/

The letters "TH" spell two distinct consonant phonemes — what phoneticians call dental fricatives:

• Voiceless /θ/ ("theta") — no vocal cord vibration. Think, three, bath, math, mouth, thought, thank, thirty.
• Voiced /ð/ ("eth") — vocal cords vibrate. This, that, the, mother, father, breathe, those, they.

These distinct sounds change meaning, as these minimal pairs prove:

The simplest test: put two fingers on your throat. Say "this" — you'll feel a buzz before the vowel. Say "think" — silence, then air. That buzz is your vocal cords. Voiced TH has it; voiceless TH doesn't. Wikipedia's analysis confirms /θ/ is pronounced with more muscular tension and stronger aspiration than /ð/.

How to Pronounce TH Sound: Tongue Position Step-by-Step

The exact movement to produce both TH sounds:

1. Open your mouth slightly. Lips relaxed — not rounded, not stretched.
2. Push the tongue tip forward until it sits lightly between your upper and lower front teeth.
3. Keep contact light. No pressing, no biting. Tongue resting on a thin pane of glass.
4. Push air through the narrow gap between the top of your tongue and the cutting edge of your upper teeth. Air flows continuously — TH is a fricative, not a stop.
5. For voiced /ð/, switch on your voice. For voiceless /θ/, keep voice off — just air.

Some native speakers place the tongue tip behind the upper teeth rather than between them. Both work. The interdental position is easier to learn because you can see it. The Cambridge Dictionary's pronunciation guide lists /θ/ and /ð/ among the most challenging consonant phonemes for English learners worldwide.

The most common mistake: keeping the tongue behind the teeth, which produces /t/, /s/, or /d/ instead of TH. If you can't see the tongue tip in a mirror when you say "think," it isn't coming out far enough. Beginners can start with our English pronunciation practice guide for beginners before drilling TH specifically.

The Voicing Rule: When TH Is Voiced vs Voiceless

There's no absolute rule, but the patterns predict roughly 90% of words.

At the start of a word:

• Function words → voiced /ð/. The, this, that, these, those, they, them, their, there, then, than, though, thus. Memorise these 15 words — the rest is voiceless.
• Content words → voiceless /θ/. Think, thing, three, thank, thumb, thick, thin, thought, theatre, Thursday.

In the middle of a word:

• Native English words → voiced /ð/. Mother, father, brother, other, weather, together, rather, either.
• Greek/Latin loanwords → voiceless /θ/. Mathematics, athlete, cathedral, method, ethics, Athens.

At the end of a word:

• Nouns and adjectives → voiceless /θ/. Bath, math, mouth, north, south, breath, truth, faith, fifth.
• Verbs (often silent -e) → voiced /ð/. Bathe, breathe, clothe, soothe, teethe.

Grammar words and verbs lean voiced; everything else leans voiceless.

Why TH Is So Hard: The L1 Substitution Map

Interdental fricatives are linguistically rare — found in fewer than 10% of the world's documented languages, per the World Atlas of Language Structures. Most languages substitute the nearest consonant from their phonological inventory, and the substitution reveals your L1.

TH-Fronting: F and V Substitutions

Swap: /θ/ → /f/, /ð/ → /v/. Think → "fink," three → "free," brother → "bruvver."

L1s: Vietnamese, Cockney English, African American Vernacular English, some Caribbean varieties.

Fix: /f/ and /v/ are also fricatives — same airflow, just lips against teeth instead of tongue between teeth. In a mirror, if your lower lip moves toward your teeth on "three," push your tongue forward instead.

TH-Stopping: T and D Substitutions

Swap: /θ/ → /t/, /ð/ → /d/. Think → "tink," this → "dis," mother → "mudder."

L1s: Quebec French, Russian, Polish, Hindi and Urdu, Latin American Spanish, Tagalog, Irish English, some German.

Fix: the "leaky T" exercise. /t/ and /d/ stop air completely; TH lets it flow. Start to say /t/, but let air escape continuously while pushing your tongue forward between your teeth.

TH-Alveolarization: S and Z Substitutions

Swap: /θ/ → /s/, /ð/ → /z/. Think → "sink," this → "ziss," mother → "muzzer."

L1s: European French, German, Japanese, Korean, Mandarin Chinese, Cantonese, European Portuguese.

Fix: /s/ and /z/ are also fricatives — perfect match in manner. /s/ uses the tongue tip behind the upper teeth; TH needs the tip between them. Push it forward 5 mm.

Alveolarization sounds most foreign to native English listeners — the highest-leverage fix for accent reduction. Spanish speakers: Castilian Spanish has /θ/ — the sound spelled "z" or "ce/ci" in zapato. Just extend it to English. Our hard English words for Spanish speakers and hardest English words to pronounce cover L1-specific fixes in depth.

The Top 20 TH Words to Master First

Frequency lists from large corpora (COCA, BNC, OpenSubtitles) show a handful of words account for most TH exposure:

13 of the top 20 are voiced /ð/. Function words dominate everyday speech. If you only fix one TH sound, fix voiced /ð/ — it appears in nearly every English sentence. Practice the first: say it 100 times in phrases. Highest-impact pronunciation drill in English.

Minimal Pairs Drill

Pick the drill matching your L1 substitution. Say each pair five times, alternating.

TH (/θ/) vs S — Japanese, Korean, French, German, Chinese: think/sink, thing/sing, thick/sick, mouth/mouse, path/pass.

TH (/θ/) vs T — Russian, Quebec French, Hindi, Spanish: thin/tin, three/tree, thought/taught, bath/bat.

TH (/θ/) vs F — Vietnamese, Cockney/AAVE: three/free, thread/Fred, thought/fought, death/deaf.

Voiced TH (/ð/) vs D — Russian, Hindi, Spanish: this/dis, that/dat, they/day, breathe/breed.

Voiced TH (/ð/) vs Z — German, French, Japanese, Korean: these/Zs, then/Zen, mother/muzzer.

Record yourself. Once you produce the contrast in isolation, move to sentences. Our English minimal pairs guide covers 200+ pairs across every problematic English consonant.

Four Self-Check Tests: Mirror, Finger, Paper, Throat

Four free techniques. No teacher needed.

Mirror test (visual): Say "think" slowly. The pink tip of your tongue must protrude between your teeth.

Finger test (tactile): Hold a clean index finger 1 cm in front of your lips. Say "thin." The tongue tip should lightly touch your finger.

Paper test (aspiration): Hold thin tissue 5 cm from your mouth. Say "think" sharply — paper jumps. Say "this" — barely a flutter.

Throat test (voicing): Two fingers on your throat. Say "this" — buzz. Say "think" — silent until the vowel.

Run all four every drill session for the first week. Muscle memory takes over after that.

When NOT to Pronounce TH (Silent TH in Fast Speech)

Native speakers don't pronounce every TH. Forcing yourself to will sound robotic.

• clothes — /kloʊz/, homophone of close. The TH is silent.
• months — /mʌns/ or /mʌnts/. The /nθs/ cluster is virtually impossible.
• fifths — /fɪfs/. The /fθs/ ending reduces.
• sixths — often /sɪks/ or /sɪksts/.

Wikipedia confirms /nθs/ is "virtually impossible to pronounce" for most native speakers. Documented native speech, not laziness.

Rule: if TH sits inside a consonant cluster surrounded by /n/, /f/, /k/, /s/ — let it reduce. Spend effort on stressed, isolated TH where meaning depends on it. Our guide to connected speech in English and English word stress explain how natives compress these clusters.

Tongue Twister Ladder

Climb slowly — speed only after accuracy.

Level 1 (Beginner): Think thin. Three thick thumbs. These three things.

Level 2 (Intermediate): Three free throws. Thanks for the thrilling thought. Both my brothers think this through.

Level 3 (Advanced):

• The thirty-three thieves thought they thrilled the throne throughout Thursday.
• I thought a thought, but the thought I thought wasn't the thought I thought I thought.
• Whether the weather is cold, or whether the weather is hot, we'll weather the weather, whatever the weather.

Record yourself and compare against a native model. For more sequences, see our 50 English tongue twisters and pair them with English shadowing exercises for natural rhythm.

Practice TH in Real Conversations with AI Feedback

Drills work for isolated sounds, but the real test is connected speech under cognitive load. Practice Me gives you real-time voice conversations with AI tutors in both American and British accents — both feature clear interdental TH. Topics that surface dozens of TH sounds per minute:

• Family: mother, father, brother, the other day, together
• Numbers: three, thirteen, thirty, thousand
• Opinions: I think, I thought, this is, that's why
• Comparisons: better than, more than, thicker than that

Run a 10-minute conversation each day, then listen to the playback. The TH sounds you keep missing will jump out. The 3-day free trial gives unlimited conversations to lock in voiced /ð/ in the, this, that, they. For broader fluency, see our guide on how to sound natural in English and our methods to improve English speaking by yourself.

Frequently Asked Questions

Is it OK to pronounce TH as F, T, or S?

For intelligibility internationally — usually yes. Research on English as a lingua franca found TH substitutions rarely cause misunderstandings. In native-speaker contexts (interviews, presentations), TH substitutions are noticeable.

Which is more important — voiced TH or voiceless TH?

Voiced /ð/ is higher priority because it appears in the most frequent function words: the, this, that, they, them, their, there, then, than. Voiceless /θ/ matters for numbers and think.

Do British and American speakers pronounce TH differently?

The TH sounds themselves are identical in standard American and British English. Differences are in surrounding vowels and rhythm. Some regional varieties (Cockney, AAVE) substitute /f/ or /t/, but those are dialect features.

Why can't I see my tongue when I say TH?

Because it's still behind your teeth. Interdental TH requires the tongue tip to protrude past the cutting edge of your front teeth — about 2-3 mm visible.

How long does it take to master the TH sound?

For motivated adults with daily 10-15 minute drills: clear production in isolation takes 1-2 weeks. Reliable production in connected conversation takes 1-3 months.

Is the TH sound disappearing from English?

In some dialects, yes. TH-fronting (TH → F/V) is spreading through younger speakers in London and parts of New Zealand. Standard American and broadcast British English still maintain interdental fricatives.