Study some information about prefixes:
1. Negative prefixes:
un-, in-, im-, il-, ir-, mis-, dis-
unable, inactive, impossible, illegal, irregular, misunderstand, disapproval
He is unable to attend this meeting.
2. Other prefixes:
re- (+ гл.), en-, em-(+ гл.), over- (+ гл.),  under- (+ гл.)
Examples: remake, embody, overproduce, underestimate
They often overproduce during the year. It is a big problem.