PRESENT CONTINUOUS AND PRESENT SIMPLE

 http://www.ego4u.com/en/cram-up/grammar/simpre-prepro

http://www.perfect-english-grammar.com/present-simple-present-continuous-2.html

http://www.englisch-hilfen.de/en/exercises/tenses/simple_present_progressive.htm

http://www.englisch-hilfen.de/en/exercises/tenses/simple_present_progressive2.htm

 http://www.englishpage.com/verbpage/verbs1.htm
 
http://www.english-4u.de/pres_prog_ex4.htm

 http://www.inglestotal.com/present-simple-and-present-continuous-diferencias-y-ejercicios/