Double letters at the end of short words: ff, ll, ss, zz, ck
Year group: 1
Source: DfE, English Appendix 1: Spelling, National Curriculum for England (2013) — Year 1
Curriculum requirement: Statutory
Purpose: Year 1 spelling guide to the ff, ll, ss, zz, ck rule — why short vowels double the final consonant, with worked examples and practice activities.
The rule
In short words with a single short vowel, the sounds /f/, /l/, /s/, /z/, and /k/ at the end are usually spelled with double letters:
- /f/ → ff: off, staff, cliff, huff
- /l/ → ll: well, bell, fill, full, pull
- /s/ → ss: hiss, miss, fuss, dress, class
- /z/ → zz: jazz, fizz, buzz, fuzz
- /k/ → ck: back, kick, duck, check, clock
Why double? The double letter signals that the vowel before it is short. A single letter after a short vowel would leave the vowel open to misreading as long.
Exceptions to know
A small number of very common words do NOT follow this pattern. Learn these individually:
| Word | Why no doubling |
|---|---|
| if | short function word — historical spelling |
| of | /ɒv/ sound, not /ɒf/ — different phoneme |
| as | short function word |
| is | short function word |
| has | short function word |
| was | short function word |
| yes | short function word |
| bus | follows the rule in some analyses |
| us | short function word |
| gas | follows the rule in some analyses |
| his | short function word |
ck — the important detail
ck is used immediately after a short vowel. After a consonant or a vowel digraph, use k alone:
- After short vowel → ck: back, deck, sick, lock, duck
- After consonant → k: bank, silk, mask, milk
- After vowel digraph → k: book, week, look, speak
Examples by pattern
-ff words: off, staff, cliff, huff, cuff, sniff, stiff, gruff, bluff, stuff, scoff, whiff, puff, buff
-ll words: well, bell, tell, sell, fell, hill, fill, pill, will, dull, full, pull, bull, ball, call, fall, hall, tall, wall, spell, shell, smell, still, spill
-ss words: hiss, miss, fuss, dress, class, grass, glass, press, stress, bless, cross, loss, boss, kiss, pass, mass, mess, less, bliss
-zz words: jazz, fizz, buzz, fuzz, whizz, razz, pizzazz
-ck words: back, pack, rack, sack, black, crack, stack, track, neck, deck, peck, wreck, check, kick, lick, pick, sick, thick, trick, lock, dock, rock, sock, knock, duck, luck, stuck, truck, block, clock, flock, shock
Word sort
Sort these words by their double letter ending.
Words: cliff · buzz · miss · back · well · jazz · huff · lock · dress · fizz · tick · bell · class · duck · full · cuff · check · hiss
| -ff | -ll | -ss | -zz | -ck |
|---|---|---|---|---|
Dictation sentences
- She sat on the cliff and could tell the buzz was getting louder.
- Fill your glass at the well at the back of the hall.
- The duck gave a kick and fell off the dock with a splash.
- Check the lock and make sure the bell is on the wall.
- The fuzz on the grass was still full of dew at dawn.
Source: DfE English Appendix 1: Spelling (2013). All examples verified against Year 1 statutory content.