I'm preparing an exercise for students to teach them the "past progressive" in German. Since this verb tense does not exist in German, I was thinking about teaching a couple sentences, a statement and a question. The sentences need to contain a contrast between the simple past and the past continuous, similar to English, so that students see the difference. Would this be alright? 1. What were you doing when I called you last night? Was machtest du als ich dir letzte Nacht angerufen habe? 2. She arrived when we were having dinner. Sie ist gekommen, als wir zu Abend gegessen. I guess in this case you could say "...beim Abendessen", but then students would not realize the verb tense contrast. Is there any website where I could find examples of this kind? Thanks so much.