Very often the past simple ends in -ed (regular verbs): I work in a travel agency now. Before that I worked in a shop. We invited them to our party but they decided not to com. But many verbs are irregular. The past simple does not end in -ed. Mozart wrote(write→wrote) more than 600 pieces of music. We saw(see→saw) Rose in town a few days ago. I went(go→went) to the cinema three times last week...