The class monitor notices that the classroom is messy after a group activity. What should the students do? (Obligation)

Rafi's teacher asks him to bring a book from the library. How will he ask the librarian for the book? (Request)

Sara's parents have asked her to complete her homework before going out to play. What should Sara do? (Obligation)

Tarek has an important exam tomorrow. He's thinking about studying late into the night.

What might happen if Tarek doesn't get enough sleep? (Possibility)

The principal needs a volunteer to help organize an event at school. How should the principal ask the students for help? (Polite Request)