"Why is there a k in knee?" is one of the fairest questions a phonics learner ever asks. Here's the honest answer, the full list of common patterns, and how to teach them without undoing the "every letter has a sound" rule you just spent months building.
Why English keeps silent letters at all
Most silent letters aren't random — they're historical leftovers. Some (like the k in knee) used to be fully pronounced in Old English and only went silent later, while spelling stayed frozen. Others were added on purpose to show a word's Latin or Greek roots (the b in debt nods to Latin debitum). Once printing standardised spelling in the 1400s-1500s, pronunciation kept drifting but spelling mostly stopped — leaving today's silent letters behind.
The 4 patterns to teach first
Other common silent letters worth knowing
| Pattern | Examples |
|---|---|
| Silent L (before d, k, m, f) | could, should, would, calm, half |
| Silent T | listen, castle, often, fasten |
| Silent H | hour, honest, ghost |
| Silent E (magic-e, different rule) | See our magic-e guide — it changes the vowel, it isn't fully "silent" |
How to teach it without confusing the phonics rules already learned
- Frame it as a short, fixed list, not a new rule. "These letter pairs are always silent" is easier to hold onto than a rule with exceptions.
- Teach one pattern at a time. Master kn- fully before introducing wr- — mixing several silent patterns at once is where confusion creeps in.
- Cross out, don't erase. Physically cross through the silent letter when writing the word — a small visual cue that it's there but not spoken.
- Wait until regular phonics is secure. Silent letters are exceptions — introduce them only once the regular rules are automatic, not while they're still being learned.
Silent letters are one piece of a bigger set of spelling exceptions — see our 10 English spelling rules and how to teach irregular words for the rest of the picture.