This PowerPoint activity includes ten questions on modals of obligation. The questions are rather simple and cover the concepts behind must, mustn't and don't have to.
How to use it in an EFL class
The PowerPoint is designed as a grammar game in EFL classes after the introduction of modals of obligation in the lesson. There may be various ways to play it, but I'll suggest playing a grammar competition among two groups. The questions come up on the interactive board with a 30-second timer and three option buttons. The options are always must, mustn't and don't have to. The group leaders should come up to the board and answer the question slides with their group members. After 30 seconds pass, the answer buttons disappear, and if your students cannot answer the question, you can review the modal concept in the question with your class. There is no time limit after the timer has run out. If the groups give a wrong answer to the question, a slide with the correct answer appears. Again, you can review the concept of the question, and there is no time limit again in wrong answer slides.