A
do
redo
happy
unhappy
legal
ilegal
able
unable
comfortable
uncomfortable
approve
disapprove
semifinal
formal
informal
honest
dishonest
logical
illogical
connect
disconnect
continious
discontinue
sociable
unsociable
understand
misunderstand
relavent
irrelevant
pilot (for a machine in a plane)
autopilot
advantage
disadvantage
atlantic
transatlantic
fortunately
unfortunately
acceptable
unacceptable
contaminate
decontaminate
pack
unpack
clockwise
counterclockwise
trust
distrust
sensitive
insensitive