Past simple

affirmative
http://www.agendaweb.org/verbs/past_simple-exercises-elementary.html
negative
http://www.agendaweb.org/verbs/past-simple-negative.html
interrogative
http://www.agendaweb.org/verbs/past-simple-questions.html

Feina colònies

Here you have a lot of exercises to practise the past simple: regular and irregular verbs.

http://www.agendaweb.org/verbs/past_simple-exercises.html
http://www.agendaweb.org/verbs/past_simple-exercises-elementary.html

http://www.macmillandictionary.com/verb_wheel/
http://esl.fis.edu/grammar/verbs/5.htm
http://www.englishpage.com/irregularverbs/interactiveirregularverbs1.htm
https://www.youtube.com/watch?v=AKaD2btS1A4