prefixes

able-unable
accurate-inacurate
agree-disagree
comfortable-uncomfortable
convinient-inconvinient
credible-uncredible
experienced-unexperienced
button-unbutton
fair-unfair
formal-informal
fortunate-unfortunate
like-dislike
pack-unpack
patient-impatient
plesant-unplesant
satisfactory-unsatisfactory
appropriate-inappropriate
sincere-insincere
do-undo
quality-disquality
tie-untie
legible-illegible
literate-illiterate
regular-irregular
responsible-disresponsible
moral-immoral
appear-disappear
read-unread
mature-immature
regular-unregular
legal-unlegal
understand-misunderstand