- http://www.englishexercises.org/makeagame/viewgame.asp?id=1965
- http://a4esl.org/q/h/9901/jd-pronouns.html
- http://www.myenglishpages.com/site_php_files/grammar-exercise-object-pronouns.php
- http://www.ego4u.com/en/cram-up/grammar/pronouns/exercises?02
- http://www.englisch-hilfen.de/en/exercises/pronouns/personal_pronouns3.htm