Past simple

http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?04

http://www.ego4u.com/en/read-on/countries/usa/tour/chicago#exercises

http://www.englishexercises.org/makeagame/viewgame.asp?id=2252

http://www.kico4u.de/english/uebungen/unregelmaverb/regel1.htm

http://www.adelescorner.org/grammar/past_tense/past_regular.html