-able and -ible are suffixes which change verbs to adjectives.
Follow the rules you know for adding a vowel suffixes.
(To review the suffixing rules, go to Unit
9)
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1. If the syllable just before the suffix -able or -ible is the stressed syllable, you will be able to hear a clear short vowel in that syllable. Therefore you will usually need a 'wall' of two consonants to protect that short vowel. For example: |
| forget + able = forgettable |
| admit + ible = admissible |
2. If the base word ends in e you can usually drop the e,
because -able and
-ible both start with a vowel. For example:
| excuse + able = excusable |
| sense + ible = sensible |
But......
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Some root words end in : -ce with the sound /s/ or -ge with the sound /j/ |
You need to make sure you do not lose these 'soft' sounds for c
and g when you add a suffix. The vowels e, i and
y make c say /s/ and g say /j/. The
letter a will not do this job so, if the suffix is -able
and the ending is -ce or -ge, you must keep the final e
of the root word. For example:
| service + able = serviceable |
| manage + able = manageable |
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Go to next page: Test yourself on the suffix rules for -able and -ible. |
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Teacher, High School, UK
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