https://www.montsemorales.com/gramatica/PastSimRegPdc.htm
https://www.montsemorales.com/gramatica/PastSregular1y2.htm
https://www.montsemorales.com/gramatica/PastSimpAffRegSw2-4.htm
http://www.focus.olsztyn.pl/en-past-simple-exercises.html#.Wduom60znVo
https://www.montsemorales.com/gramatica/PastSimpAffIrregSw2-4.htm
http://baladre.info/english/sedaviwebfront/pastregular.htm
https://www.ego4u.com/en/cram-up/grammar/simple-past/exercises
http://www.myenglishpages.com/site_php_files/grammar-exercise-simple-past.php
https://www.ego4u.com/en/cram-up/tests/simple-past-1
https://www.ego4u.com/en/cram-up/tests/simple-past-1