How to Pronounce the TH Sound (Both of Them)

English has two TH sounds, and most languages have neither. That combination is why TH is the single most reliable giveaway of a non-native accent — and also why it is one of the most fixable, because the tongue position is simple once someone tells you what it is.

The two sounds

Both are written with the same two letters, which is a genuine flaw in English spelling — nothing on the page tells you which one to use. See why English spelling drifted from its sounds for how that happened.

How to make it

1. Put the tip of your tongue lightly against the back of your top front teeth. Not between them clenched, not behind them — just touching.
2. Leave a gap. Air has to escape. If you seal the contact you will produce a T or D instead.
3. Push air out. Breath only, no voice: that is /θ/ as in think.
4. Now add voice. Same tongue position, vocal cords on: that is /ð/ as in this.

A useful check: put a finger on your throat. On this you should feel a buzz. On think you should feel nothing. If both feel the same, you are producing one sound for both — which is the most common error even among speakers who have the tongue position right.

Many teachers say to stick your tongue out between your teeth. That does produce a valid TH, and it is a useful exaggeration while learning, but native speakers rarely do it — the contact is usually just behind the teeth and barely visible. Aim for the visible version first, then pull it back as it becomes automatic.

Which one goes where?

The distribution is not random, and three patterns cover most cases:

• Grammar words take /ð/ — the, this, that, these, those, they, them, their, then, than, there, though. Nearly every common TH word that is a pronoun, article or conjunction is voiced.
• Content words usually take /θ/ — think, thing, three, thick, thin, thank, throw, north, tooth, path, month. Nouns, verbs and adjectives starting with TH are almost always voiceless.
• Between two vowels it is usually /ð/ — mother, father, brother, other, weather, gather, either, rather. Compare author and ether, which keep /θ/ because they came into English from Greek and Latin.

There is also a small set where a final voiceless TH becomes voiced in the verb form: breath /θ/ → breathe /ð/, bath → bathe, cloth → clothe, mouth (noun) → mouth (verb). Notice the spelling often adds an e as a hint.

The four substitutions, and what each one costs you

When a language lacks TH, its speakers reach for the nearest sound they do have. Which substitute you use is largely predictable from your first language:

Two of these actually create real word collisions, which is why they matter more than the others: think/sink, thing/sing, three/free, thin/fin, mouth/mouse. Drill those as minimal pairs rather than in isolation — hearing the contrast is what trains it. Start with three vs tree and think vs sink.

Worth saying plainly: the F/V substitution is standard in several native English accents, including large parts of London. TH-fronting is not an error there — it is the local variety. If your goal is to be understood rather than to match one prestige accent, see whether you actually need to lose your accent.

Why it feels harder than it looks

The tongue position takes about thirty seconds to learn. The difficulty is elsewhere: TH is a weak sound. It carries very little acoustic energy compared with S or T, so in connected speech it is easy to lose entirely — especially in clusters like sixths or clothes, which even native speakers simplify. And if your first language files TH under an existing category, your ear may not register the difference at all at first. That is a perception problem, not a muscle problem, and it is covered in why you can’t hear the difference between two English sounds.

A five-minute practice routine

1. Isolate. Hold a long /θθθθ/ for five seconds, then switch to /ðððð/ without moving your tongue. Feel your throat for the switch.
2. Word-initial. think, thing, three, thick — then this, that, they, then.
3. Word-final, which is harder: bath, path, month, both, teeth.
4. Contrast pairs against your own substitute. If you say “sink” for “think”, alternate the two aloud until they feel distinct.
5. In a sentence, where it actually has to work: “I think this thing is worth three months.”

Check yourself out loud with the pronunciation checker — if the recogniser keeps hearing “sink” when you say “think”, you have concrete evidence rather than a guess.

Related

/θ/ and /ð/ drill pages · all 44 English sounds · guides for your native language · connected speech