'ch' and 'th' Sounds: Free KS1 Phonics Worksheet

What are the 'ch' and 'th' digraphs?

A digraph is two letters that together represent one phoneme (a single unit of sound). In 'ch' the c and h combine to make the sound you hear at the start of chair, cherry and chip. In 'th' the t and h combine to make the sound you hear at the start of thumb, thistle and thirteen. Most school phonics programmes teach both in Reception and keep practising them in Year 1. The 'th' sound is worth a special mention because it actually has two pronunciations: a 'voiced' version (as in this and that) and an 'unvoiced' version (as in thumb and thin). For this worksheet the focus is simply on spotting the spelling pattern, so children do not need to distinguish between the two.

How to use this worksheet at home or in class

Print the sheet and read each picture name aloud together, sounding it out slowly so the child can hear the very first sound: ch-ch-chair, th-th-thumb. Encourage the child to say the digraph sound rather than the individual letter names. They can colour the pictures first to settle in, then fill in the missing letters one word at a time. If a child writes c or t on its own, say the word again and ask, ‘Is that one sound or two letters?’ — the answer is one sound, written with two letters. A common mix-up is between 'ch' and 'sh', so it can help to hold a hand in front of the mouth: ‘ch’ is one short puff of air, while ‘shhh’ can keep going.

Why digraphs matter for early reading

Once children can blend single letter-sounds, digraphs are often the next hurdle. Without recognising that 'ch' and 'th' are single sounds, a child may try to read chip as 'c-h-i-p' and become stuck. Teaching digraphs as a single, recognisable unit prevents this and supports the systematic synthetic phonics approach used across English schools. Knowing the common digraphs opens up a large number of everyday words, such as chip, much, this and with. Completing words with the right pair of letters, as in this worksheet, reinforces that letters can team up, an idea children will revisit with 'sh', 'ng', 'qu' and other digraphs and trigraphs.

Extending the activity

After completing the sheet, turn it into a quick word hunt. Ask the child to find more things around the room that begin with 'ch' (a chair, a chest, a chin) or 'th' (a thumb, a thread, the number three). You could also gather a few household objects or picture cards and ask the child to physically sort them into a 'ch' pile and a 'th' pile. For children ready for more, try listening for the digraphs in the middle or at the end of words, such as teacher, bath and tooth. Short, playful repetition over several days helps these sounds become automatic.

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