https://eingleses.com/ejercicios-de-presente-simple-vs-presente-continuo/
https://www.englisch-hilfen.de/en/exercises_list/pronomen.htm
https://agendaweb.org/vocabulary/time-exercises.html
https://agendaweb.org/verbs/to-be-exercises.html
https://www.englisch-hilfen.de/en/exercises/tenses/simple_present_progressive2.htm#google_vignette