This unit we're studying the PAST SIMPLE tense. Watch this video about how to form it and when to use it: https://www.youtube.com/watch?v=xLA58CSIf3M Notice that the verb TO BE and the modal verb CAN are irregular and they don't follow the rules. The past simple of TO BE is WAS or WERE and the past simple of CAN is COULD. Finally, here you'll find a list of irregular verbs that may be useful: https://aprendemasingles.com/wp-content/uploads/2012/07/lista-de-verbos-irregulares-en-inglecc81s.pdf