https://pollylingu.al/en/es/lessons/1627
https://agendaweb.org/grammar/personal-pronouns-exercises.html
https://agendaweb.org/verbs/to-be-exercises.html
https://www.perfect-english-grammar.com/present-simple-exercise-11.html
https://agendaweb.org/verbs/present_simple-exercises.html
https://www.really-learn-english.com/simple-present-exercises.html#01