I use this activity with my Spanish II students to practice answering questions using negative words. This could be used with higher level Spanish classes as well to review. The basic premise is that each student has a question that he/she will be asking a partner, who in turn will respond correctly in the negative. Students then trade questions, find another student and repeat the process. My students enjoy this activity and I find that I have to stop them after 15-20 minutes so that we can move on to another activity.