To transform verbs from Present to past, all irregular verbs must include the ending -ed.However, there are certain Rules for that transformation.
Play---->Played
Study--->Studied---> the Y becomes i and -ed is added.
Like---> Liked---> As this word ends with e only a d is necessary.
Pie de foto: : Example of how to add -ed to Regular verbs.
To practice the structures seen, solve the following pages:Past Simple To Be:http://s.mound.free.fr/skyblues67/simppast/wascloze.htmhttps://www.usingenglish.com/quizzes/77.htmlPast Simple regular verbs:http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_ed2.htmPast Simple Irregular Verbs:http://www.englisch-hilfen.de/en/exercises_list/verbs.htm (varios ejercicios para trabajar.)Past Simple Practice:http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_mix.htmhttp://www.myenglishpages.com/site_php_files/grammar-exercise-simple-past.php (a veces esta página marca las respuestas correctas como erróneas.)https://www.ego4u.com/en/cram-up/grammar/simple-past (en esta página está la explicación y más abajo los ejercicios.)Imágenes:http://3.bp.blogspot.com/-HebqKBBvUBE/U4b117N6tKI/AAAAAAAADb4/ZdRhhoalhC4/s1600/pastsimple+to+be+cha...
https://englishprojectoxford.files.wordpress.com/2014/02/past_simple.gif
https://mafaldamundo.files.wordpress.com/2012/11/pasado-simple.jpg?w=690&h=575