The principle underlying the difference between words ending in -able and those ending in -ible is thus stated by The Oxford English Dictionary (s.v. -ble): ‘In English there is a prevalent feeling for retaining -ible wherever there was or might be a Latin -ibilis, while -able is used for words of distinctly French or English origin.’ The following are examples of words ending in -ible:
accessible
addible
adducible
admissible
audible
avertible
collapsible
comprehensible
controvertible
credible
discernible
discerpible
edible
eligible
existible
expressible
extendible
feasible
fencible
flexible
forcible
incomprehensible
incorruptible
incredible
indefeasible
indefensible
indelible
indestructible
indigestible
intangible
intelligible
irresistible
legible
negligible
ostensible
permissible
persuasible
plausible
producible
reducible
remissible
reprehensible
reversible
tangible
vendible
visible
SOME WORDS ENDING IN -ISE or -IZE
The following spellings are those adopted for The Oxford Dictionary:
actualize
advertise
advise
affranchise
aggrandize
agonize
alcoholize
alkalize
anathematize
anatomize
anglicize
apologize
apostrophize
apprise (to inform)
apprize (to appraise)
authorize
baptize
brutalize
canonize
capitalize
capsize
carbonize
catechize
categorize
catholicize
cauterize
centralize
characterize
chastise
christianize
cicatrize
circumcise
civilize
collodionize
colonize
communize
comprise
compromise
contrariwise
conventionalize
corporealize
criticize
crystallize
demise
demoralize
deodorize
desilverize
despise
devise
discolorize
disfranchise
disguise
disorganize
dogmatize
dualize
economize
emphasize
emprise
enfranchise
enterprise
epigrammatize
epitomize
equalize
eternize
etherealize
etymologize
eulogize
euphonize
evangelize
excise
exercise
exorcize
experimentalize
extemporize
familiarize
feminize
fertilize
formalize
fossilize
franchise
fraternize
gallicize
galvanize
generalize
germanize
gormandize
gothicize
graecize
harmonize
hebraize
hellenize
hibernize
humanize
hydrogenize
hypnotize
idealize
idolize
immortalize
improvise
incise