Questions with how, comparatives and superlatives

How + adjectives
http://www.examenglish.com/grammar/A2_How_questions.htm
http://www.engames.eu/how-in-questions/
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-26551.php
http://www.grammar.cl/Games/Question_Words_2.htm

Can / could
http://www.english-grammar-lessons.com/could/exercise3.swf
http://www.perfect-english-grammar.com/modal-verbs-of-ability-exercise-1.html
http://www.englishexercises.org/makeagame/viewgame.asp?id=7710
http://www.esl-lounge.com/student/grammar/1g101-elementary-can-could-gap-fill-exercise.php
http://mbonillo.xavierre.com/exercises/eso2/2esowint09/cancould2eso3.htm

Comparatives and superlatives
http://www.eslgamesplus.com/comparatives-superlatives-wild-zoo-animals-vocabulary-grammar-interactive-monkey-fun-activity/
http://www.grammar.cl/Games/Comparatives_Superlatives.htm
http://www.englishexercises.org/makeagame/viewgame.asp?id=6009
https://www.ego4u.com/en/cram-up/grammar/adjectives-adverbs/adjectives/exercises
http://www.myenglishpages.com/site_php_files/grammar-exercise-grammar-comparatives-superlatives.php


Hints for teacher
https://tefltastic.wordpress.com/worksheets/grammar/comparative-superlative-games/
http://busyteacher.org/14341-comparative-superlative-activities-how-to-teach.html
http://www.onestopenglish.com/grammar/grammar-reference/adjectives/comparative-and-superlative-adjectives-tips-and-activities/144844.article
http://www.usingenglish.com/articles/fun-practice-for-comparative-adjectives.html