Excellent pages of grammar exercises:
- http://www.englisch-hilfen.de/en/exercises_list/alle_grammar.htm
- http://www.agendaweb.org/index.php
- http://baladre.info/english/sedaviwebfront/grammarindex.htm#pronouns
- http://www.myenglishpages.com/site_php_files/grammar.php
- http://www.englishpage.com/grammar/index.html