In a nutshell

The suffixes '-able' and '-ible' are used to turn verbs into adjectives. Words ending in these suffixes often sound the same but they are spelt differently. In this summary you'll learn which words are spelt with '-able' and '-ible'.

The suffix '-able'

The suffix '-able' is usually used if you can hear the whole root word before the ending.

Examples

verb	*Rely*	*Adapt*	*Prefer*
Adjective	*Reli*able	*Adapt*able	*Prefer*able

Note: If there's a consonant before a 'y', it often changes to an 'i', For example, deny becomes deniable.

Root words ending in 'ce' and 'ge'

If the root word ends with 'ce' or 'ge', you must keep the 'e' when you add the suffix.

Examples

Verb	Manage	Knowledge	Notice
Adjective	Manageable	Knowledgeable	Noticeable

The suffix '-ible'

The suffix '-ible' is usually used if you can't hear the whole root word before the ending.

Examples

'Visible' has the suffix 'ible' as 'vis' isn't a whole root word.

'Incredible' has the suffix 'ible' as 'incred' isn't a whole root word.