This is a great exercise from the fantastic website Englishpage.com. It is an activity that helps you practice the difference between 'Must' and 'Have to'.http://www.englishpage.com/modals/interactivemodal2.htm It is quite a difficult exerciose because you need to think about:
- Positive and Negative such as Don't have to and Must not
- The past had to and the future will have to.
Some of the vocabulary in the sentences is quite difficult, so I would recommend this activity for Upper Waystage students and above.