How to Pronounce TH in English (Think vs This), for Spanish Speakers

The, this, that, think, thanks, with. TH appears in some of the most frequent words in English, so if it comes out as de, dis, dat, tink or tanks, listeners notice it many times per minute. The good news: it’s one of the easiest sounds to fix, and if you speak Spanish, you probably already make it without knowing.

Two different TH sounds

English spelling uses th for two sounds ^[3]:

Sound	Symbol	Voice?	Examples
Voiceless TH	/θ/	No	think, three, thanks, month, both, math, birthday
Voiced TH	/ð/	Yes	the, this, that, they, mother, other, breathe, with*

* With is said both ways by native speakers.

The mouth position is identical. The only difference is whether your vocal cords vibrate. Put your fingers on your throat: for think you feel nothing at the start; for this you feel a buzz.

A useful rule: voiced /ð/ appears in common grammar words (the, this, that, these, those, they, them, there, then, than) and between vowels in many words (mother, father, weather, other). Voiceless /θ/ appears in most content words starting with TH (think, thing, thank, three, Thursday, theory) and in many endings (month, health, fifth, truth).

How to make the sound

1. Tongue tip forward. Place the tip of your tongue lightly against the back of your upper front teeth, or just slightly between your teeth. Don’t bite it, don’t press hard.
2. Let air flow. Push air out over the tongue. It must be continuous, like a long ssss, not a quick pop. Linguists call this a fricative: the air rubs through a narrow gap ^[1].
3. Add voice for /ð/. For this, turn on your voice while keeping the same position and airflow ^[2].

Test yourself: you should be able to hold the sound for two or three seconds: θθθθθ-ink, ððððð-is. If you can’t hold it, your tongue is blocking the air, and you’re making a T or D.

You already have these sounds in Spanish

This is the secret most courses don’t tell Spanish speakers:

• /θ/ in Spain. In most of Spain, the z and the c before e/i (zapato, cerca, gracias) are pronounced with a sound very close to English voiceless TH ^[1]. If you speak Spanish from Spain, say cerca and then think with the same first sound.
• /ð/ everywhere. In practically all varieties of Spanish, a d between vowels is soft, as in nada, cada, todo or dedo (the second d). That soft d is very close to English voiced TH ^[2]. Say nada slowly, notice where your tongue is on the second d, and use that sound for the and mother.

Latin American speakers don’t usually have /θ/ (cerca is said with an S), but the soft d of nada still gives you /ð/, and from there voiceless /θ/ is just the same position without voice.

Common substitutions (and why they matter)

You say	Listener may hear	Example
T for /θ/	tank, tree, tin	thank → tank, three → tree, thin → tin
S for /θ/	sink, sank, mouse	think → sink, mouth → mouse
F for /θ/	free, fought	three → free, thought → fought
D for /ð/	dare, day, den	there → dare, they → day, then → den

Context usually saves you (nobody thinks you mean I tank you), but each substitution adds a small effort for the listener and makes your accent more noticeable.

Practice pairs (minimal pairs)

Say each pair, making the difference clear. Record yourself and listen back:

• T vs /θ/: tank / thank · tree / three · tin / thin · tie / thigh · boat / both
• S vs /θ/: sink / think · sick / thick · mouse / mouth · pass / path · face / faith
• D vs /ð/: dare / there · day / they · den / then · dough / though · breed / breathe

Practice phrases

Start slowly, then speed up while keeping the air flowing:

• Thank you for the thought.
• I think this is the third thing.
• They’re over there with their mother.
• Both of them think the theory is worth it.
• Thursday the thirteenth.
• This, that, these and those.

The TH in fast speech

Here’s what makes this less scary: in natural, fast speech, native speakers often make the voiced TH in the, this, that very short and light, sometimes barely touching the teeth. After an N or L, it can even blend into the previous sound (in the → i-nə, all the → a-lə). So don’t over-pronounce it. A big, slow, tongue-out TH in every the sounds unnatural too. The goal is a light, quick, continuous sound.

Remember also that the is usually a weak form, thə, not thee. See schwa and weak forms.

Keep it in proportion

TH is very noticeable, but it’s not what makes you hard to understand. Listeners recover from a wrong TH easily; they struggle much more with misplaced word stress or flat rhythm. Fix TH because it’s quick and visible, then spend most of your practice time on prosody.

Free tools for practice

• YouGlish: search think, the other or throughout and watch dozens of native speakers’ mouths.
• Rachel’s English: detailed videos on mouth position for American English sounds.
• Sounds of Speech: animations of how each English sound is made.
• Forvo: hear any word by different native speakers.

For the full list of habits Spanish speakers bring into English, read pronunciation mistakes Spanish speakers make.