Spelling rule
-able or -ible?
Both endings mean 'can be' or 'is'. As a rule of thumb, -able goes on a whole word you can still see, and -ible on a part that isn't a word on its own.
How it works
- 1
A whole word before it: -able
- enjoy → enjoyable
- depend → dependable
- comfort → comfortable
- avail → available
- reason → reasonable
- 2
Drop the e before -able, unless it keeps a c or g soft
- value → valuable
- adore → adorable
- notice → noticeable
- change → changeable
- 3
Not a whole word before it: usually -ible
- possible
- horrible
- terrible
- visible
- incredible
- 4
-ably and -ibly for the -ly forms
- probable → probably
- possible → possibly
- comfortable → comfortably
- horrible → horribly
Watch out
- There are exceptions both ways: sensible and responsible use -ible although sense and response are words; capable and vulnerable use -able although there's no whole word before the ending.
Words to practise
Years 3 and 4 statutory words
- possible
- probably
Years 5 and 6 statutory words
- available
More everyday words
- enjoyable
- comfortable
- valuable
- horrible
- visible
- sensible
Practise a few minutes a day
The daily spelling workout brings back the words your child finds tricky, and shows you which rules they need to revisit.