What Is a Trigraph?

In phonics, a trigraph is three letters that spell one sound. Catch has five letters and three sounds: c, a, tch. The three letters are not doing three jobs. They have combined into one.

The three your child will actually meet are tch, dge and igh, in catch, badge and night. Two of them follow the same rule, and it is worth learning as one thing rather than two: straight after a short vowel you write tch and dge, and everywhere else you write ch and ge. Catch and badge, but lunch and cage. Igh follows no rule at all and is learned as a spelling to recognise.

Trigraphs usually arrive in first and second grade, after sh, ch and th are solid. Below: what a trigraph is, how it differs from a digraph, the three patterns with their word lists, the rule, the mix-ups to expect, and a five-step routine for teaching one at the kitchen table.

What is a trigraph?

A trigraph is three letters that spell a single sound. The test takes a finger: cover the tch in catch and the word loses exactly one sound, not three. What is left is “ca”, which is where the word breaks, so the tch was one piece.

Trigraph is a teacher’s word and a linguist’s word, which is why most parents first meet it on a school worksheet rather than in conversation. It is also used in linguistics for three-letter combinations in other languages, and in computer programming for something unrelated entirely. This page is only about the reading kind: three letters, one sound, in English words a child under eight reads.

Your child does not need the word. They need to see the three letters as one unit, because a child who reads catch as c-a-t-c-h gets a word that does not exist.

What is the difference between a digraph and a trigraph?

Only the number of letters. A digraph is two letters spelling one sound: sh, ch, th, wh, ph, ck. A trigraph is three: tch, dge, igh. Nothing else about them differs, and a child reads both the same way.

	Letters	Sound	Examples
Digraph	2	1	ship, chip, bath, duck
Trigraph	3	1	catch, badge, night

The useful way to hold it is that English often writes one sound with more letters than it needs, and the count is the only thing that changes. Ck, tch and dge are the same idea at two letters and three, which is also why ck words and tch words follow rules of the same shape.

The three trigraphs your child will meet

Three patterns cover almost every trigraph word a young child reads. Each has its own word lists and worksheets.

Trigraph	The sound it makes	Example words	Where it appears
tch	the same sound as ch	catch, match, fetch, itch, kitchen	End of a word, and in the middle
dge	the same sound as j	badge, bridge, fudge, edge, judge	End of a word, and in the middle
igh	long i, the name of the letter	night, light, right, high, bright	Middle of a word, and at the end

Tch never starts an English word, and neither does dge. Both need a vowel in front of them, which is a clue to the rule below rather than an accident. The tch word list and the dge word list have them family by family with printable sheets.

Igh is the odd one out, and in two ways: it spells a vowel sound rather than a consonant one, and it follows no rule, so night, light and sight are learned as spellings rather than chosen. It is one of the ways English writes a long i, which is where the long i word list takes it up, beside the silent e in bike and the y in my.

The tch and dge rule, in one line

Straight after a short vowel, write tch and dge. Everywhere else, write ch and ge.

• tch after a short vowel: catch, fetch, itch, notch, hutch
• ch after a consonant or two vowels: lunch, porch, peach, coach
• dge after a short vowel: badge, edge, fudge, dodge, judge
• ge after a long vowel or a consonant: cage, huge, large, change

Four common words break the tch half: much, rich, such and which. They are learned as words rather than treated as evidence against the rule, and they are worth learning cold, because a beginning reader meets all four constantly.

The dge half has a reason behind it that children like: English words do not end in j. When a word ends with that sound, it gets dge or ge instead, which is why there is a choice to make at all. Our spelling rules guide sets both rules beside the -ck rule they are shaped like, and the 2nd grade -ch and -tch words and -ge and -dge words are the sorts that practise the choice.

The mix-ups that slow children down

Four of them, and each one tells you something different.

Reading tch as two sounds. A child who says “cat-ch” has met the t and the ch separately and is doing exactly what they were taught. Cover the three letters, say the single sound, and reread the word whole.

Writing cach for catch. This is the rule not yet learned, not a hearing problem: nothing in the sound of the word says the t is there. Show the pattern and practise one family at a time.

Writing luntch for lunch, or cadge for cage. This is the opposite, and it is a better sign than it looks. Your child has learned the pattern and is applying it everywhere, which is what learning a rule looks like before the exceptions land. The fix is the contrast rather than more practice: lunch has a consonant in the way, cage has a long vowel.

Writing nite for night. Both spellings say the same thing, and your child has chosen the reasonable one. Igh is a spelling to recognise, so this is a word-by-word correction rather than a rule to teach.

How to teach a trigraph at home

One pattern at a time, and read it before you spell it. The routine below takes about five minutes and works for tch and dge alike. Teaching one pattern at a time in a planned order is what the National Reading Panel’s 2000 report calls systematic phonics, and the panel found it helps children from kindergarten through sixth grade.

1. 1

   Say the sound before you show the letters

   Say catch, match and fetch and ask your child what they hear at the end. It is the same sound as the end of much. Nothing is written down yet, because the point of this step is that the ear hears one sound, not three letters.

2. 2

   Show the three letters as one piece

   Write tch on a single card, not three cards, and say the one sound it makes. This is the whole idea, and it is the step children skip when they meet the trigraph inside a word first. Three letters, one sound, one card.

3. 3

   Read words that use it

   Start with one family, where the trigraph is the only new thing: catch, match, patch, hatch. Have your child read across the word rather than naming letters. If they stall, cover the tch with your finger, say its sound for them, then uncover and let them finish.

4. 4

   Spell words with sound boxes

   Say a word and have your child write it, one box per sound. Catch gets three boxes and five letters, because tch fills one box on its own. Spelling is the harder direction and it is where you find out whether the pattern is really known, since nothing in the sound tells a child the t is there.

5. 5

   Find it in a real book

   Hunt for tch or dge on a page or two of any picture book. Catch, watch, kitchen, bridge and edge turn up constantly in early readers. Finding the pattern in text your child did not practise with is what turns a taught pattern into one they own.

The sound-box step is the one that does the most work. One box per sound means tch gets a box to itself, so catch is three boxes holding five letters. That picture is the whole idea made physical, and sound boxes are the sheet to use for it.

Games and activities for trigraph words

Five minutes, with what is already in the house.

• Family sort. Write eight cards, four -atch and four -etch, and have your child sort them into two piles and read each pile down.
• Odd one out. Say catch, match, patch, lunch. Which one does not belong? This one is oral, and it is the fastest check of whether the ear has it.
• Finger cover. Read a word with the trigraph covered, then uncovered. Silly the first few times, then quick.
• Kitchen hunt. Kitchen, watch, fridge and badge are all in most houses. Point at the thing, say the word, write it together.
• Spell it back. You read the word, your child writes it. Three words is a round, and stopping while it is still easy is the point.

When do children learn trigraphs?

Reading them comes first, usually in first grade, and spelling them reliably comes in second. The order is the same everywhere: single letters, then the consonant digraphs, then these.

Common Core RF.1.3.a asks first graders to know the spelling-sound correspondences for common consonant digraphs, which is the rung before this one. The spelling half lands a year later: L.2.2.d asks second graders to “generalize learned spelling patterns when writing words”, and its own example is cage to badge, which is the dge rule exactly.

The readiness signal is worth more than the grade. Your child is ready when short vowels are solid and ch and ge are already familiar, because both rules are questions about the vowel in front of them. A child still working out cat and hop is not ready, and the fix is to go back rather than to push on.

Free trigraph word lists and worksheets

Three places to practise, and they do different jobs.

• Tch words: the tch words by family, with word cards, sound boxes and spelling sheets.
• Dge words: the same for dge, and the dge, ge or j question that no rule sheet answers.
• Long i words: where igh belongs, beside the other ways English writes a long i, with its own sheets.
• 2nd grade -ch and -tch words and -ge and -dge words: the sorts that practise the choice itself, inside the whole second-grade list.