You won't have to teach grammar anymore, just let the "Piensapapel" do it for you! They contain examples of a grammar concept, and through questions and instructions, guide the students to discover the grammar concept on their own.
I give these sheets to students the day before we go over the grammar concept. They come to class with the completed sheet, and take a bell-ringer quiz on that grammar concept. Then we go over what they didn't understand and review anything they might need. I allow