Here is an activity using a grammar "something, somebody, someday, anything, anybody" etc. This activity is effective because the grammar in Japanese is a little confusing. They need some activities to use the grammar without thinking too much about the conjugation and everything. Anyway here are the steps.
Divide the class into half. Half of the class will be suspects and the other half will be detectives. Then distribute a schedule to the suspects. There should be a couple of criminals in class.
Last night, the JPNS102 final exam was stolen from Ikeda-sensei’s office…
Detectives, ask each person 3 questions with
“Did you hear/see something at ~ o’clock ?”
Suspects, answer “No, I heard nothing. I did ~ at ~ o’clock” or
“Yes, I heard/saw something.
Detectives, when you know what time the crime happened, go back to the person who did nothing at that time – that’s the criminal! Go ahead to arrest the criminals!