TH Digraph Words

What Is the TH Digraph?

A digraph is two letters that work together as one spelling unit, standing for a single sound rather than two — but TH is one of the more unusual digraphs in English, because T and H together spell two closely related sounds rather than just one. Neither sound is the /t/ that T usually spells or the /h/ that H usually spells; both are made with the tongue between or near the teeth.

TH is also one of the most common digraphs in everyday English, appearing in some of the most frequently used words in the language, including the, they, and this. A child who spells TH confidently gets an outsized boost in everyday reading and writing simply because these words come up so often.

Two Sounds, One Spelling

The two TH sounds are usually described as voiced and unvoiced. In a voiced TH, like the one in that, this, and them, the vocal cords buzz while the sound is made. In an unvoiced TH, like the one in think, math, and bath, the same tongue position is used, but there’s no buzz — just a quieter puff of air.

Both versions are spelled exactly the same way, which is the most important thing to understand about this pattern: a learner never has to decide which TH sound a word uses in order to spell it. Spelling-wise, TH is TH.

Voiced TH (throat buzzes)	Unvoiced TH (no buzz)
that, this, them	think, math, bath

Where TH Shows Up

TH shows up at the beginning and the end of high-frequency words:

Position	Example words
Beginning	that, this, think
End	math, bath, path

Because so many everyday words rely on this digraph — from the and this to think and bath — practicing TH pays off well beyond the words on this page.

A Different Kind of Contrast

Most digraph pages contrast their sound with a nearby digraph, but TH’s most useful contrast is internal: voiced versus unvoiced, within the pattern itself, rather than TH versus a different letter pair. That’s the Level 1 distinction worth giving real attention here — not because it changes spelling, but because a learner (or a parent reading this list aloud) may otherwise wonder why they and think don’t sound alike despite starting the same way on the page.

Common TH Mistakes

The most frequent spelling slip is writing a single letter, usually a plain t or d, for the full TH sound — writing tat for that or tink for think. Slowing the word down and confirming there’s a soft, continuous TH sound rather than a hard, single-letter stop usually resolves this.

When TH Sounds Like F, V, D, or T

Separately from spelling, TH is often pronounced in ways that don’t match the descriptions above, and it’s worth knowing that these are two different situations:

• In young children’s developing speech, TH is one of the later sounds to settle, so hearing wif for with or dis for this is a common and expected stage. It typically resolves on its own; a speech-language professional is the right person to consult if there’s any concern.
• In a number of established dialects, these same pronunciations are simply how the words are said by fluent adult speakers — not an immature or incorrect version of some other accent.

In both cases the point for spelling practice is the same: the word is written with th regardless of how it’s pronounced. There’s no need to change a learner’s pronunciation before spelling practice can succeed, and no reason to treat a dialect pronunciation as something to correct.

How to Practice TH Words

1. Say the target word aloud.
2. Stretch it into its sounds together, treating TH as one sound rather than two letters (th… i… n… k).
3. Write or type the letters for each sound, in order.
4. Read the result back exactly as written.

If a word comes out wrong, step 4 is the key one: read back exactly what was written — “that says tink” — and let the learner listen for which sound needs to change, rather than pointing to the correct letters directly. Hearing the mismatch themselves is what builds the skill; being handed the answer skips it.

Signs the TH Pattern Is Becoming Secure

Signs the pattern is becoming secure include:

• Hearing TH as one sound in a new, unfamiliar word, whether it’s the voiced or unvoiced version.
• Spelling both voiced and unvoiced TH words the same way, without hesitating over which “kind” of TH a word uses.
• Reading a TH word not seen before.
• Spelling a representative TH word from dictation.
• Explaining, in their own words, that TH can sound two different ways but is always spelled the same.