Activities to solve online with answer keys:
- http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/regcom.htm
- http://www.members.iinet.net.au/~adelegc/grammar/comparatives/comparatives1.html
- http://www.members.iinet.net.au/~adelegc/grammar/comparatives/comparatives2.html
- http://www.members.iinet.net.au/~adelegc/grammar/comparatives/comparatives3.html
- http://www.members.iinet.net.au/~adelegc/grammar/comparatives/superlatives.html
- http://www.members.iinet.net.au/~adelegc/grammar/comparatives/superlatives2.html
- http://web.archive.org/web/20070411000522/http://www.englishoutlook.com/Focus/grammar/comp3.html
- http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/regcom1.htm
