Look at this presentations to udnerstand comparatives and superlatives better. Then do the activitie suggested! Enjoy!
When you finish, you can practice by doing the activities suggested:
1. http://www.ego4u.com/en/cram-up/grammar/adjectives-adverbs/adjectives/exercises
2.http://www.theyellowpencil.com/gramacomparativos.html
3. http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/regcom1.htm