ESO 1 Extra practice

http://www.learnenglish-online.com/grammar/tests/superlativecomparative.HTML

http://www.english-zone.com/spelling/comp5.htm

http://www.learnenglishfeelgood.com/english-comparative-superlative1.HTML

http://www.ego4u.com/en/cram-up/grammar/adjectives-adverbs/adjectives/exercises