How to pronounce -ed
https://www.englishclub.com/pronunciation/-ed.htm
IRREGULAR VERBS
http://www.englisch-hilfen.de/en/exercises/irregular_verbs/forms.htm
http://www.englisch-hilfen.de/en/exercises/irregular_verbs/fill_in.htm
http://www.englisch-hilfen.de/en/exercises/irregular_verbs/mix.htm
PRESENT PERFECT:
http://www.adelescorner.org/grammar/pres_perfect/pres_perfect_1.html
https://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises
http://www.agendaweb.org/exercises/verbs/present-perfect-multiple
http://www.adelescorner.org/grammar/pres_perfect/pres_perfect_1.html
https://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises
http://www.agendaweb.org/exercises/verbs/present-perfect-multiple