COMPARATIVE FORM

http://www.agendaweb.org/grammar/comparative-adjectives-exercises.html

http://www.learnenglish-online.com/grammar/tests/comparativeadjectives2.html

http://www.language-worksheets.com/comparative-adjectives-elementary.html

https://learnenglishkids.britishcouncil.org/en/grammar-practice/comparatives-and-superlatives