Detectives

1. Send one student (the 'detective') outside, and ask another student for something that belongs to him or her, but is not easily identifiable - a pencil, a standard textbook, etc.
2. The detective comes back and the student gives him the pencil.
3. The detective asks the students: "Is this yours?"
4. The student - whether it is in fact his or hers or not - denies it: "No, it isn't mine. It's his." (points to another student)
5. The detective then asks the student indicated, and so on round the class;
6. At the end, the detective has to try to identify who in fact was lying and is the owner of the object.