2nde - Exercises on OBLIGATION-PERMISSION-PROHIBITION

 here are some exercises for you to pratice.

http://www.englishexercises.org/makeagame/viewgame.asp?id=1568

http://englishingambier.over-blog.com/ext/http://bebos.chez-alice.fr/mon_site_web/doc/rules_exercises.pdf

http://www.anglaisfacile.com/exercices/exercice-anglais-1/exercice-anglais-887.php

http://s.mound.free.fr/skyblues67/modals/mustn%27t.htm

http://absolutenglish-972.pagesperso-orange.fr/notes/prohibition/docu.htm