Present Simple or Present Continuous exercise 1
http://www.englisch-hilfen.de/en/exercises/tenses/simple_present_progressive.htm
Present Simple or Present Continuous exercise 2
http://www.englisch-hilfen.de/en/exercises/tenses/simple_present_progressive2.htm
Present Simple or Present Continuous exercise 3
http://www.englisch-hilfen.de/en/exercises/tenses/simple_present_progressive3.htm