Endings: -able/-ably and -ible/-ibly
Year group: 5/6
Source: DfE, English Appendix 1: Spelling, National Curriculum for England (2013) — Years 5–6, Suffixes
Curriculum requirement: Statutory
Purpose: Years 5–6 guide to -able/-ably and -ible/-ibly — rules for choosing the right form, statutory examples, and practice activities.
The rule
Both -able and -ible mean "capable of being" or "worthy of being." Both are pronounced the same (/əbəl/). The correct choice depends on the base word.
Use -able when:
- The base word is a complete English word: comfort → comfortable, wash → washable
- The base word ends in -e (usually drop the e): adore → adorable, love → lovable
- The base word ends in -ce or -ge (keep the e): notice → noticeable, manage → manageable
- The base word has a related -ation form: consider → consideration → considerable
Use -ible when:
- The base is NOT a complete English word: poss- → possible, hor- → horrible
- The base word ends in -ss: access → accessible, express → expressible
- The base word ends in -miss or -mit: permit → permissible, omit → omissible
- The base has a related -ion form (not -ation): digest → digestion → digestible
-able words
| Word | Base | Note |
|---|---|---|
| adorable | adore (drop e) | capable of being adored |
| comfortable | comfort (complete word) | providing comfort |
| considerable | consider → consideration | large or important |
| noticeable | notice (keep e before -able) | able to be seen |
| manageable | manage (keep e before -able) | able to be dealt with |
| changeable | change (keep e) | likely to change |
| knowledgeable | knowledge (keep e) | having knowledge |
| understandable | understand (complete word) | able to be understood |
| miserable | miser- — but close to complete word | very unhappy |
| valuable | value (drop e) | having great worth |
| enjoyable | enjoy (complete word) | giving pleasure |
| reliable | rely → reli- + -able | able to be trusted |
| reasonable | reason (complete word) | fair; logical |
| available | avail + -able | able to be used or obtained |
| fashionable | fashion (complete word) | following current fashion |
| charitable | charit- + -able | generous; relating to charity |
| tolerable | toler- + -able (toleration exists) | able to be tolerated |
| imaginable | imagine → imagin- + -able (imagination exists) | able to be imagined |
| despicable | despic- + -able | deserving hatred |
| applicable | applic- + -able (application exists) | relevant; able to be applied |
-ible words
| Word | Note |
|---|---|
| possible | poss- not a complete word |
| impossible | im- + possible |
| responsible | respons- + -ible |
| terrible | terr- not a complete word |
| horrible | horr- not a complete word |
| incredible | incred- not a complete word |
| visible | vis- (see) — not a complete word; vision → -ible |
| invisible | in- + visible |
| accessible | access (ends in -ss) |
| sensible | sens- + -ible (sensation → not -ation linked in same way) |
| flexible | flex- + -ible |
| eligible | elig- not a complete word |
| digestible | digest → digestion → -ible |
| permissible | permit → permission → -ible |
| divisible | divide → division → -ible |
| compatible | compat- not a complete word |
| legible | leg- (read) — not a complete word |
| edible | ed- (eat) — not a complete word |
| audible | aud- (hear) — not a complete word |
| reversible | revers- + -ible |
The adverb forms: -ably and -ibly
When you add -ly to an -able or -ible adjective, you get an adverb:
- adorable → adorably
- comfortable → comfortably
- possible → possibly
- terrible → terribly
- sensible → sensibly
The rule: change -able to -ably and -ible to -ibly. The spelling of the adjective tells you how to spell the adverb.
Common mistakes
| Wrong | Right | Reason |
|---|---|---|
| posible | possible | -ible not -able; base not a complete word |
| noticable | noticeable | keep the e from notice before -able |
| adoreable | adorable | drop the e from adore before -able |
| terreable | terrible | -ible; base not a complete word |
| responsable | responsible | -ible |
| visiable | visible | -ible; vision → -ible |
| comfortible | comfortable | -able; comfort is a complete word |
Decision tree
Is the base word a complete English word? YES → probably -able (comfortable, enjoyable, reliable) BUT: does it end in -ce or -ge? YES → keep the e: noticeable, manageable NO → usually drop the e: adorable, lovable NO → probably -ible (possible, terrible, horrible) ALSO -ible when: base ends in -ss (accessible) ALSO -ible when: related noun ends in -ion not -ation (visible/vision)
Word sort
Complete word or not? Sort accordingly.
Words: comfortable · possible · noticeable · terrible · reliable · visible · manageable · horrible · reasonable · sensible · adorable · responsible · enjoyable · incredible
| -able (complete base word / -ation linked) | -ible (incomplete base / -ion linked) |
|---|---|
Dictation sentences
- It was possible but not comfortable — and barely manageable in the heat.
- The incredible view was visible for miles and made every step worthwhile.
- She was responsible for making the event enjoyable and memorable for everyone.
- The decision seemed reasonable and considerable thought had gone into it.
- Noticeable changes are not always desirable — sometimes sensible is preferable.
Source: DfE English Appendix 1: Spelling (2013). Decision rules derived directly from the statutory guidance. All word examples verified against statutory lists and standard British English usage.