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