Explanation: https://www.ego4u.com/en/cram-up/grammar/simpas-paspro
Exercise 1: https://learnenglish.britishcouncil.org/en/grammar-reference/past-continuous-and-past-simple
Exercise 2: http://www.perfect-english-grammar.com/past-simple-past-continuous-exercise-1.html
Exercise 3: http://www.englishgrammarsecrets.com/pastsimpleorcontinuous/menu.php
Exercise 4: http://www.englishpage.com/verbpage/pastcontinuous.html
Exercise 5: http://www.5minuteenglish.com/mar10.htm
Exercise 6: http://www.ecenglish.com/learnenglish/lessons/past-simple-vs-past-continuous
Exercise 7: http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_progressive.htm
Exercise 8: http://www.englishexercises.org/makeagame/viewgame.asp?id=734
Exercise 1: https://learnenglish.britishcouncil.org/en/grammar-reference/past-continuous-and-past-simple
Exercise 2: http://www.perfect-english-grammar.com/past-simple-past-continuous-exercise-1.html
Exercise 3: http://www.englishgrammarsecrets.com/pastsimpleorcontinuous/menu.php
Exercise 4: http://www.englishpage.com/verbpage/pastcontinuous.html
Exercise 5: http://www.5minuteenglish.com/mar10.htm
Exercise 6: http://www.ecenglish.com/learnenglish/lessons/past-simple-vs-past-continuous
Exercise 7: http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_progressive.htm
Exercise 8: http://www.englishexercises.org/makeagame/viewgame.asp?id=734