Make negative: logical
illogical
Make negative: interesting
uninteresting
Make negative: rational
irrational
Make negative: able
unable
Make negative: legible
illegible
Make negative: probable
improbable
Make negative: polite
impolite
Make negative: visible
invisible
Make negative: legal
illegal
Make negative: relevant
irrelevant
Make negative: happy
unhappy
Make negative: correct
incorrect
Make negative: official
unofficial
Make negative: formal
informal
Make negative: patient
impatient
Make negative: responsible
irresponsible
Make negative: usual
unusual
Make negative: regular
irregular
Make negative: possible
impossible
Make negative: comfortable
uncomfortable