unti-, co-,dis-, ex-,il-, in-,im-, ir-, inter-, mis-, over-,un-,re-.
1 crowded
2 interested
3 author
4 mature
5 tell
6 important
7 behaving
8 polite
9 necessary

1 overcrowded 2 uninterested 3 co-author 4 immature 5 retell 6 unimportant 7 misbehaving 8 impolite 9 unnecessary