Práctica
https://www.spanishdict.com/quizzes/41/ser-vs-estar
http://personal.colby.edu/~bknelson/SLC/ser_estar.html
https://studyspanish.com/grammar/test/serest1
https://studyspanish.com/grammar/test/serest2
https://studyspanish.com/grammar/test/serest3
https://studyspanish.com/grammar/test/serest4
https://www.quia.com/cm/25812.html?AP_rand=492425160
https://www.quia.com/ba/73907.html?AP_rand=1357449960
http://personal.colby.edu/~bknelson/SLC/ser_estar.html
https://studyspanish.com/grammar/test/serest1
https://studyspanish.com/grammar/test/serest2
https://studyspanish.com/grammar/test/serest3
https://studyspanish.com/grammar/test/serest4
https://www.quia.com/cm/25812.html?AP_rand=492425160
https://www.quia.com/ba/73907.html?AP_rand=1357449960