Adjectives

Here are a couple of links to a website where you'll be able to practice all kinds of grammar exercises. These links refer to gradable and non-gradable adjectives and adjectives with -ed and -ing:

http://www.ejerciciodeingles.com/como-utilizar-adjetivos-acabados-ed-ing-ingles/

http://www.ejerciciodeingles.com/adjetivos-graduables-no-graduables-ingles/

Questions and Auxiliaries

Here are a couple of interesting links to practice auxiliaries and questions:

A quiz to practice word order in questions:

http://esl.about.com/library/quiz/blgrquiz_questionforms.htm

- Yes/No Questions:

http://esl.about.com/b/2010/10/22/are-you-learning-english-yes-i-am-no-im-not.htm?nl=1

- Auxiliaries:

http://esl.about.com/od/grammarintermediate/a/a_auxiliary.htm

and an auxiliary verb quiz:

http://esl.about.com/library/quiz/bl_auxiliary.htm