Exercises

1:Don't park your car on bends. It is illegal. - You park your car on bends.



2:Perhaps she will agree with it. Who knows? - She agree with it.

3:I want you to tidy the classroom. - You tidy the classroom.


4:I need your help. It's too much work for me. - You help me.


5:Look at that baloon. It's over there. - you see the balloon?


6:Don't worry about dinner. I'll make it. - You worry about dinner.



7:Why don't you stay with us? No problem! - You stay with us.


answers:
1)must not / cannot 
2)may / can
3) must
4) must
5) Can
6) need not
7) can / may


For more practice : http://www.englishpage.com/modals/modalintro.html